It’s almost a physics equation: The more beloved the series and the longer it remains on the air the higher expectations ratchet up for the show’s final episode to deliver something brilliant. For every series finale that lived up to the tone and scope of the seasons that came before (‘Newhart,’ ‘Friday Night Lights,’ ‘Cheers,’ ‘The Wire’), there are many that failed to distinguish themselves one way or another. But a lower circle of TV hell is reserved for the finales listed below, which were so bizarre, ridiculous or infuriating, you might have had difficulty deciding why you liked the show in the first place. Before we begin, one note about two series you won’t find on this list: ‘Seinfeld’ and ‘Lost.’ Both show’s finales have become cultural punching bags since they aired, largely because expectations were insanely high (Jerry and the gang would have their funniest escapade ever, and the ‘Lost’ writers would explain every little mystery, right?). In each case, many fans got stuck on what the finales weren’t and missed what they were. Both finales were ambitious and memorable curtain-closers that stayed true to the identities of their characters (the “no hugging, no learning” ethos of ‘Seinfeld’ and emotional finality for those living in limbo on ‘Lost’). OK, enough defending. Let’s throw some finales on the fire. Multiple spoilers ahead because, duh, we’re talking about how shows ended.

‘Dexter’ ‘Remember the Monsters?’ – Sept. 22, 2013 A couple seasons after the Showtime series’ high-water mark of season four (featuring John Lithgow’s Trinity Killer), many fans were ready to Saran wrap ‘Dexter’ to their tables when the show found a creative resurgence in season seven (thanks, in part, to Yvonne Strahovski’s Hannah McKay). But that glimmer of hope only added to the disappointment surrounding the plodding yet scattershot eighth season, capped off with a finale that could have only been predicted by Monty Python. Everybody: “Dexter’s a lumberjack and he’s OK ... ” The metaphors (there’s a hurricane coming for Miami, get it?) were as ham-fisted as the acting (the show’s increasing reliance on Jennifer Carpenter’s shrieking to convey emotion). In the end, the writers waffled on taking a hard look at their central character, only to let the show bleed out in a deeply unsatisfying middle ground.

‘Battlestar Galactica’ ‘Daybreak’ – March 13-20, 2009 No less a sci-fi/fantasy authority than George R. R. Martin took to the Internet to express his disgust with ‘BSG’s’ two-part, three-hour final episode (say what you want about ‘Dexter,’ but at least it kept its crappy ending to less than 60 minutes). Although opinion was divided on the finale, Martin and others complained about an end that relied too heavily on a higher power and was way too pat (especially for a show that had resisted such neatness in the past). In the overly talky episode, viewers learned that the survivors of the battle with the Cylons ditched all of their advanced technology to start a new civilization – which, 150,000 years later, we would know as Earth. Minds blown … but not really. The worst part was the continued use of ‘All Along the Watchtower,’ tied to footage of popping-and-locking 21 st century robots destined to eventually become our Cylon enemies. Mwah-ha-ha-ha. Ridiculous.

‘St. Elsewhere’ ‘The Last One’ – May 28, 1988 We might be able to trace every “crazy twist” ending of the past 25 years to the finale of ‘St. Elsewhere.’ In the last episode, viewers discovered that every dramatic or comedic development over the past six seasons had been a figment of autistic Tommy Westphall’s imagination as he played with a St. Eligius snow globe. (Seriously, who would buy a hospital snow globe for a kid? It’s not much better than a shirt that reads “I underwent treatment for my disorder at St. Eligius and all I got was this lousy T-shirt.”) Although the final scene was ballsy and memorable, it also kinda invalidated everything fans had enjoyed during the show’s run. As such, it earns a place on this list. But one fantastic side effect from ‘The Last One’ is the Tommy Westphall Universe. Due to character crossovers (and other references between series), some have concluded that hundreds of television series took place in Tommy’s brain. That means that he’s responsible for both ‘Arrested Development’ and ‘Joanie Loves Chachi.’

‘Roseanne’ ‘Into That Good Night’ – May 20, 1997 Speaking of twist endings, ‘Roseanne’ offered up a heck of a pretzel in its two-part finale. At the end of nine seasons, it was revealed – via an awkward voice-over – that the show we had been watching was just Roseanne Conner’s fictionalized memoirs. The good news: The conceit invalidated the series’ mediocre final season, in which Roseanne won the lottery. The bad news: It erased just about everything else we thought we knew about the Conners. It turned out that Mark and Darlene were together, and so were Becky and David. Bev wasn’t gay, Jackie was gay and Dan never recovered from his heart attack and was dead. Bummer. For a show that prided itself on finding humor in the often dire reality of lower-middle-class America, the final turn was too strong of a sucker punch.

‘Quantum Leap’ ‘Mirror Image’ – May 5, 1993 While we’re on the subject of downer finales, here’s one that wasn’t necessarily intended to be that way. With the series on the cancellation bubble, series creator Donald P. Bellisario wrote the season five closer as a cliffhanger to be resolved in the fall of 1994. But when ‘Quantum Leap’ was euthanized by NBC, the episode was hastily edited to bring closure to the series. Dr. Sam Beckett, who’s been attempting to fix others’ wrongs by leaping into their bodies and hoping that eventually he’ll eventually become himself again, leaps into a mining town on the exact hour and date of his birth. Although he meets the man who’s been controlling him and is told he can return to his life whenever he wants, he chooses against this option in favor of leaping again to tell the wife of his buddy Al that Al is still alive. As for Sam, a postscript could only tell us, “Dr. Sam Beckett never returned home.” This was the end fans got, made maddeningly worse by NBC’s promos that promised that this was “the leap you’ve been waiting for – the final leap!” Ugh.

‘Dinosaurs’ ‘Changing Nature’ – July 20, 1994 Roseanne’s life was considerably sadder that we thought and Sam Beckett never got back to his real life, but at least those series didn’t end with the soul-crushing death of every character on the show. But that’s how the Jim Henson-created creatures of ‘Dinosaurs’ said goodbye to a four-season run on ABC. The last episode of the TGIF staple even came with a warning in ‘TV Guide’ that it might not be appropriate for younger viewers. Fair enough, considering that in the finale we learned that the planet was doomed, largely because Earl had attempted to manipulate nature and accidentally caused the ice age. The final scenes played out with the Sinclair family huddled together in winter clothing, pledging to stay together until the end. Heavy. Somehow a goofy sitcom starring cartoony Dinosaur puppets had become a Bergman film.

‘Heroes’ ‘Brave New World’ – Feb. 8, 2010 Honestly, it’s a little unfair to have NBC’s ‘Heroes’ on this list – unfair to the other shows, that is. The other nine series had something resembling a legacy (however faded) when it came time for their finales. Meanwhile, ‘Heroes’ couldn’t even manage to land its season one finale (way to spend all season building up to a big battle in which nothing’s at stake and the special effects are sub-‘Sharktopus’). The promise of this sci-fi series – superhumans cope with their powers in modern society – always remained exactly that: promise. And that was never more clear in the season four (and series) finale, in which superhero fights are expected but never delivered, no one seems to be in any particular danger and, like in other possible climaxes, nothing really happens at all. Because ‘Heroes’ hadn’t been cancelled yet, show creator Tim Kring finished the episode by starting a new “volume,” in which Hayden Panettiere’s Claire Bennet healed herself in front of TV cameras. Panettiere pulled an even better trick two years later when she turned into an actually interesting character on ABC’s ‘Nashville.’

‘Alias’ ‘All the Time in the World’ – May 22, 2006 By season five, J.J. Abrams’s spy thriller had tangled itself into such a mess of mythology that not even the most brilliant of finales could have undone the Gordian Knot. But ‘All the Time in the World’ was content to use the knot as a punching bag. It just piled character death on top of character death then flashed forward to a sappy ending that didn’t make much tonal or logical sense. Yep, there’s Sydney Bristow and Michael Vaughn married and living on a beach with their two kids, one of them named for Sydney’s dead dad. Well, doesn’t that just give you the warm fuzzies? ABC must have known they had a real clunker on their hands, killing it off on a Monday night dominated by ‘24’ and ‘Two and a Half Men.’

‘Little House on the Prairie’ ‘The Last Farewell’ – Feb. 6, 1984 If only the great Laura Ingalls Wilder had the foresight to end her series of autobiographical novels in a fiery explosion that consumed her whole town. Yes, that’s exactly what the TV version of ‘Little House’ did in a two-hour special that served as the series finale (the show had been cancelled after nine seasons, but was allowed to wrap up over the course of three TV movies). Star Michael Landon wrote, directed and starred in this stunner, in which the residents of Walnut Grove decide they’d rather blow up almost all of their town before they hand it over to railroad tycoon Nathan Lassiter. Yeah, that’s the perfect end to ‘Little House,’ a series that was characterized by hasty acts of violence, dramatic explosions and hell-bent destruction. The last image is of bunnies frolicking outside the (still-standing) little house. Perhaps Landon was hoping for an animated spin-off titled ‘Little Hutch on the Prairie’?

‘How I Met Your Mother’ ‘Last Forever’ – March 31, 2014 This most recent example of a flubbed finale proves that showrunners can overthink and overplan their endings. According to ‘How I Met Your Mother’ creators Carter Bays and Craig Thomas, the final 10 minutes of ‘Last Forever’ were conceived (and even partially filmed) back in 2006, just after the sitcom began its nine-season run on CBS. In a way, the writers painted themselves into a corner with certain details (Barney and Robin divorcing, “the mother” dying) that didn’t jibe with the series’ later seasons. Most fans actually liked Barney and Robin together and were frustrated that their big wedding was built up over a whole season just for their marriage to end in a flash. The same goes for the goodwill that Tracy (“the mother”) garnered in season nine, and it seemed unnaturally cruel for her to die in a line of dialogue. Perhaps the final moments of ‘Last Forever’ would have suited ‘HIMYM’ if it had only lasted a few years. After nearly a decade on the air, these characters grew beyond what they were in the first 22 episodes and the finale should have too. No high fives this time. Next: The 15 Most Memorable TV Deaths