This time of year, I get a lot of "So what's good on TV?" chitchat when I'm at parties. I rattle off the usual suspects, both new ("Reaper," "Pushing Daisies," "Mad Men") and older ("The Office," "Friday Night Lights"), then inevitably make the mistake of bringing up

"Dexter."

"Oh, what's that?" they'll ask.

"It's this drama on Showtime," I'll explain, "about a guy who works as a police scientist by day, and at night as a serial killer who only hunts other serial killers."

At this point, they'll start taking two steps back and looking frantically for someone -- anyone -- else to talk to, while I smile blandly and insist, "It's really good!"

Not that it matters to these partygoers who all assume I have something scary down in my basement, but "really good" drastically undersells "Dexter." It's an exciting, funny, moving -- and, yes, twisted -- drama that's one of the best things on television. Season one, adapting the Jeff Lindsay novel "Darkly Dreaming Dexter," introduced us to Dexter (Michael C. Hall from "Six Feet Under") and explained that a childhood trauma left him with no recognizable human emotions and an uncontrollable urge to kill. Through flashbacks to his relationship with policeman foster father Harry (James Remar), we learned that Harry convinced Dexter to channel his bloodlust in a constructive way. So he only targets other serial killers, the worst of the worst, and uses a Batman-esque array of detective and fighting skills to find them and erase them from existence. Season one also introduced the Ice-Truck Killer, a rival murderer who seemed to know an awful lot about Dexter -- because, as we learned, he was Dexter's long-lost brother, forever altered by the same trauma that transformed Dexter. Forced to choose between the kindred brother he never knew and normal, law-enforcing foster sister Deb (Jennifer Carpenter), Dexter went with the latter, killing his brother to save Deb. That choice -- plus the watchful eye of Sgt. Doakes (Erik King), the one cop in Miami who can smell the monster on Dexter -- has him seriously off his game as season two begins. He takes pity on one potential victim and lets him go, and bungles repeated attempts to take out another. "I don't normally seek human contact in times of failure," Dexter explains to us, en route to visit girlfriend Rita (Julie Benz). "But then, I don't normally experience failure." I'm not one for serial killer torture porn like "Criminal Minds" or the "Saw" movies, but what makes "Dexter" appealing is what a surprisingly light touch the show has. It's not so much a thriller as a black comedy of manners, as Dexter tries to make his way in the world given the emotional handicaps he's been given -- like, you know, being a soulless killing machine. In one of the most promising developments of the season, Dexter has to attend Narcotics Anonymous (it's a long story) and discovers that the 12-step world can speak to a mass murderer as well as to a heroin addict. Where too many other current shows use voiceover narration for exposition or forced wackiness, Dexter's running monologue is essential. Since we in the audience are the only ones who know who and what Dexter really is, he needs to be able to address us directly about his feelings, or lack thereof. So when the police uncover evidence of Dexter's previous killings and Deb is assigned to the task force -- not realizing that her target is her own brother -- Dexter complains, "I wish my own sister weren't hunting me. Makes for an awkward family dynamic." The hunt for Dexter -- or, as he's dubbed, to Dexter's displeasure, "The Bay Harbor Butcher" -- brings in a new character, FBI profiler Frank Lundy (Keith Carradine), and it's to the writers' credit that they don't try to turn the audience's sympathies against the guy. He seems like a decent, hard-working man who even takes Deb under his wing to help her recover from her involvement in the Ice Truck Killer case. There's a moment where Lundy's chatting with Dexter, co-worker to co-worker, and notes, "The worst killers in history are the ones who think the murders were somehow just." Because Dexter's victims are always so evil, we're inclined to root for him, but moments like that -- or one in where Dexter admits he doesn't really care about saving innocents, just scratching his itch to kill -- gives the show more moral complexity than you would expect, and it's the better for that. Dexter's the main character, and Michael C. Hall is playing him with an enormous amount of commitment and charm, yet there's a part of me that hopes Lundy and Deb catch him. The only other show in recent memory to offer that much ambiguity in the portrayal of its main character was "The Sopranos." If there's a series on television right now that deserves to be mentioned as a successor to the ambition and dark brilliance of "The Sopranos," it's "Dexter." And if people at parties would stop looking at me like I want to chop them into little pieces, I would explain all of that to them.

"Dexter" (Sunday at 9 p.m. on Showtime) Dexter (Michael C. Hall) tries to get his serial killing groove back as the second season begins.

Alan Sepinwall may be reached at asepinwall@starledger.com