"I'm actually sweating right now," said Jonny Lieberman. He adjusted his glasses, wiped his brow, and sucked in a deep, long breath. "It had me working, but, yeah. Wow."

He unbuckled from Subaru's 305-hp WRX STI Launch Edition. The all-wheel-drive sled, in iconic blue paint with gold wheels, looked as if it mistakenly bypassed the Oregon Trail Rally's start line, ripped off its sponsor decals, and somehow ended up in Lieberman's possession near Westlake Village, California. It's one of only 1000 headed to the U.S.

But Jonny wasn't the only one having fun. Carlos Lago and I each disembarked from intriguing, turbocharged rides: Carlos from BMW's 320-hp, $46,045, 2014 M235i and I from Mercedes-Benz's 355-horse, $60,625, 2014 CLA45 AMG.

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See all 58 photos

See all 58 photos

Right then we realized that ranking these three 300-plus-hp turbocharged, enthusiast-aimed rides wouldn't be as clear-cut as we expected, because, despite their glaring dissimilarities, their effect on our endorphins was immensely similar. It didn't help that their performance stats practically mirrored each other. On the 1.6-mile Streets of Willow race course with racer Randy Pobst behind the wheel, for instance, only 0.25 second separated fastest from slowest.

This would be a heady battle, a clash of four-wheeled factories of fun whose entertainment values would not be quantified by one of testing director Kim Reynolds' pricey instruments, but by our honed backsides. We stood laughing for a bit, shaking our heads, wondering how everything would pan out. "I LOVE CARS!" yelled Lago, flailing his arms for comic relief. But when the laughter subsided it was time to get down to the business of finding a winner.

The Radical Redhead

The CLA45 AMG is a mesmerizing little Benz. Its contentious lines, the hand-built brawn beneath the bulbous hood, the cushy interior dressed with fancy stitching, the more than $12,000 worth of options -- it's 100 percent AMG wrapped in a tiny made-for-America four-door package. And, as expected, it's pricey: Try more than $17 grand more (base price for base price) than the ubiquitous CLA250 showcased on billboards across the nation. Most of that dough pays for the transversely mounted 2.0-liter inline-four turbo, a magnificent engine.

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See all 58 photos

"Look, 355 horses from a 2.0-liter engine is just nuts," noted Lieberman. "As fast as the M235i and STI are, the AMG just laughs at them."

The Dunlop Sport Maxx RTs apply a maximum 332 lb-ft to the ground at only 2250 rpm. From then on, thrust came abundantly, tinged with rowdy burps from the quad tailpipes as upshifts clicked off. Still, each of the seven-speed's shifts occurred with an inexplicable pause, even in Benz's sportiest Manual mode—unusual for a true twin-clutch. This proved frustrating. Languid throttle response in nearly all situations also marred the experience.

"In Sport mode, matching engine speed during automatic, mid-corner downshifts seemed to take longer than necessary," said Lago. "In Manual, watch out for that rev limiter! It's punishing when it cuts in. This twin-clutch pales in comparison with BMW's eight-speed auto."

But, my, its speed. The twin-scroll turbo's 26 psi of max boost surges high into the 6250-rpm range, shoving the driver and front passenger into the $2250 Recaros with nearly as much force as in a 530-hp SL63. It's utterly shocking. The 45 needs only 4.2 seconds to get to 60 mph -- that's sports car territory -- while the quarter mile comes in 12.7 seconds at 110 mph, by far the quickest and fastest of the bunch.

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See all 58 photos

On a twisty road, the 45's electronically activated 4Matic all-wheel drive and brake-actuated Curve Dynamic Assist take over, planting the four Dunlops on the pavement without fuss. AMG's traction and stability controls grant some leeway here, furthering the car's controllability, yet the dashboard lights flashed more often than in the others. The chassis, saddled with a 60/40 weight distribution, reacted as if more mass was aft, exhibiting some mild oversteer at turn-in and a hint of plowing when prodded aggressively.

Plain and simple, straight-line speed is the CLA45's signature move. It's classic AMG. However, it's this uncanny, technologically drenched athleticism that makes the front-drive-biased Benz the least emotive -- and least comfortable, thanks to an extra-firm suspension -- on a winding road. The speed is almost too easy, too clinical: an 11 on a scale of 10. Too bad emotion isn't on the same level.

Randy's notes: "On-power understeer is a downside for the handling; balance on corner entry is an upside. It has a really impressive 2.0-liter. "

Streets of Willow Lap: 1:26.20

The Bavarian Ballerina

Whereas the CLA45's audacity broadens AMG's reputation and reach, the M235i's 15-plus M badges do little to enrich that of M GmbH's. It's embarrassing overkill that's almost as disingenuous as a 750i wearing M placards won on eBay.

But that embarrassment dwindles as you settle in. Fine Dakota leather swathes the interior, which is bedecked with black and Estoril Blue accents. It's sporty, not mesmerizing. You'll have to option it for glitz.

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See all 58 photos

Indeed, Subaru and Mercedes trumped BMW in the amenities department. But the M's lack of internal fanfare is offset by its clean, handsome physique. Such cues as the muscular front apron and large four-piston brakes effectively hint at the machine's power.

Comprehending the M's character took little effort when hustling among the canyons: a few degrees tilt of the thick helm, a stab of the attentive throttle, one snappy downshift from the eight-speed automatic. Everything's tuned for dynamism. You feel it. You hear it. The rear 245/35R18 Michelin Pilot SuperSports dug in feverishly, tidily converting the 3.0-liter inline-six's 330 lb-ft into a smooth surge. The M235i meticulously sliced through the bends, with variable steering that served up an ideal weightiness, albeit with little tactility. "This is a solid-driving car," Lago opined. "Good fundamentals: powerful engine, rear drive. It's the basics."

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See all 58 photos

The M put down numbers that would make an extinct 335-horse 1 Series M nervous. Sixty mph came in just 4.4 seconds (the 1M did it in 4.2), and the quarter mile in 13.0 seconds at 106.6 mph (the 1M did 12.8 seconds at 110.2 mph). It ran our figure eight in 24.9 seconds at an average 0.78 g -- the 1M did it in 24.7 seconds at an average 0.81 g. The two posted identical lateral acceleration of 0.97 g. Among its two rivals, the M235i was a mid-packer, equaling the STI's and CLA's skidpad performances and barely edging out the STI in acceleration. Its brake pedal took some getting used to (too mushy when charging at 10/10ths), but fade was never an issue and its 60-0 braking was the group's best at 103 feet. We had mixed feelings about its real-world ride quality. "I think it has the worst ride of this group," said Lieberman. "It's sprung softer than the STI and AMG, but it just doesn't eat up bumps as well. Too many secondary motions."

We couldn't help but think that in a near-luxury car, some, if not all, of the absent amenities—satellite radio, navigation, rearview camera, heated seats -- should come standard. And you'd expect that, as an M Performance car, oil and coolant temperature gauges -- or even a mechanical limited-slip differential (optional) and bigger brakes (optional) -- would be included. Then again, those upgrades will likely be standard weapons in the forthcoming M2's arsenal.

The M235i is two notches above the CLA45 AMG when fun is factored in, mostly for its sublime balance and smooth moves. It's a superb rear-drive coupe that boosts your heart rate and puts a grin under your nose -- just not as hastily as a $38,000 Subaru with gold shoes.

Randy's Notes: "This is the best-handling production BMW I've driven in 10 years. This car is well-balanced. What a pleasure!"

Streets of Willow Lap: 1:26.37

The Gunma Goliath

Every inch of the WRX Launch Edition's high-strength steel body exudes naughtiness. It's a mesomorphic object with a Ph.D. in Speed.

"This is a car for crazy people," Lago said. "See that wing? The wheels are gold, for crying out loud!" Lieberman noted, "You have to work hard in the STI to drive fast, but what's wrong with hard work?"

Indeed, the STI isn't for everyone. I's loud (though not as sonorous as before), has a firm ride (though not as jarring as the CLA45's nor as bouncy as the M235i's), and, yes, it brandishes a comically massive wing that does in fact serves a very small downforce function.

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See all 58 photos

The STI's inverted front struts, forged aluminum L-arms, and thicker anti-roll bars made it ride tautly atop the Palisades. The rear's A-arm and toe-control-link configuration comes from the model year prior (now with pillow-ball bushings), as does the hydraulic steering (now with a quicker 13.1:1 ratio) and 2.5-liter horizontally opposed four. Last gen's three differentials—electronically locking (center), helical limited-slip (front), and Torsen limited-slip (rear)—also remain to distribute torque 41:59 between axles. Active Torque Vectoring applies braking to the inside front wheel for surer footing.

Grace isn't the STI's strong suit. Bludgeoning is. Hurling it at a corner requires acute driver interaction. Multiple rows of the short-throw six-speed lever were needed to keep the boxer-four churning above 4000 rpm, keeping it in the zone where all 290 lb-ft are accessible. At least engineers spaced its pedals perfectly for the task. The 13-inch Brembos proved unflappable, demanding much from the sticky Dunlops, which shrugged off the stress gracefully.

All the while, the STI's trifecta of intelligent differentials distributed power seamlessly, preserving a deceptively hurried clip. Two things became noticeable at this point: how articulately the flat-bottom steering wheel communicated, and how calm the chassis remained, with no tendency to understeer on these back roads.

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See all 58 photos

The STI is skilled at carrying a substantial pace through tight curves, but not necessarily out from them. Even so, attacking another bend required little patience. The STI arrives at 60 mph in 4.6 seconds, slower than the M235i (4.4) and the CLA (4.2), yet significantly quicker than its predecessor (5.0). Quarter mile? That requires 13.1 seconds at 104.4 mph, a smidge behind the BMW. Stopping from 60 mph was accomplished in 108 feet.

The STI is verifiably sticky, with a max lateral acceleration of 0.97 g, and it made a figure-eight run of 24.9 seconds at 0.79 g, matching the BMW's time and besting it in average grip. The CLA managed a quicker lap, but just matched the STI's lateral acceleration. Which is to say the STI can keep up with the Germans, or, in the case of lapping Streets of Willow, outrun them. It can also carry three backseat joyriders without bruising their foreheads (ahem, CLA45) and happily play in the dirt.

"Even without a power bump, 305 horsepower in a 3500-pound vehicle is nothing to sneeze at," said Lieberman. "And since the STI is able to carry so much speed through corners, it's only in comparison with the two Germans that it feels 'slow. '"

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The WRX STI is the car you drive passionately, with occasional pinches of craziness. When you do, it shellacs switchbacks and then pleads for more. Its character, and the totally engrossing effect it has on its driver, is much greater than any numbers put on paper.

"This car is relentless," said Lago. "And it makes you relentless, too. You have no fear in this thing, just confidence."

The inputs and decisions you must undertake so as to not flummox its stride may be laborious at 10/10ths, but that's the beauty of this beast. You learn from it. It's a driving experience that transcends the globs of sweat coming from your pores and the inevitable traffic violations you'll accumulate. It's a vehicle that's thoroughly engaging and highly organic in feel.

I unbuckled happy, chortling even, for I'd just been flogging a sedan that offers more amenities, equal performance, and, most important, more fun than its pricier German rivals. And, oh, yeah, it has that glorious wing bolted to its trunk. For all this, the WRX STI is our number-one fabricator of fun.

Randy's Notes: "It's a great driving experience overall. But for me, it's still dominated by a frustration with understeer. Its high-speed stability…so good!"

Streets of Willow Lap: 1:26.12

3rd Place: Mercedes-Benz CLA45 AMG

Big on speed, style, and price; small on emotion.

2nd Place: BMW M235i

A well-balanced rear-driver in need of options for pizzazz.

1st Place: Subaru WRX STI

Launch Edition: Loud, fast, surefooted, amenity-packed—it typifies fun.