This post is only for those who care about "Buffy the Vampire Slayer." Those who snark at it should just ignore this.
My first thought is that, despite a general raise in quality for the last half of season 7, I'd much prefer s5 as an ending. S6 had its moments, in this first half, but generally went down hill. This could be the curse of Marti Noxon, but I also think that most of the themes had been played out by the final season. Throughout s6 and s7 there seemed to be a hole where the humor and pathos of Buffy had previously existed. Part of that might be the lack of Giles for most of the season, or the unconvincing BuffyxSpike moments. But I think there was something else.
A big part of s7's failure can be blamed on the too-many-characters syndrom most shows end up suffering from. The addition of the Potentials served a plot purpose, but there were too many to care about them. Also, it's hard to take a show where you have watched the protagonists grow from sophomoes to post-collegiates (kind of sort of) and then add a bunch of 15-year-olds into the mix. This lesson should have been learned from the addition of Dawn.
Secondly, s7 spent a lot of time re-treading the same well-worn paths in a less convincing manner. The apocolypse, and the chaos and conversations that come from it, have been covered in pretty much every concievable way by s7. There is no secret betrayal that hasn't been pulled or sudden love connection that hasn't been attempted. The former allies have been regrouped constantly and the phenomonel new power has been revealed myriad times. The only point that seemed new was Buffy being betrayed/let go by her friends-- she's disappeared on a them a few times, but they've never really completely rejected her leadership before. Yet the addition of Spike as her staunch ally and the one episode this arc was given stole any thunder that might have come from it.
I give my props to the following, however: Principal Wood. He added a nice X-Factor to the proceedings before blowing it all in the 4th to last episode. I was glad he survived. I also thought "First Dates" was an overall great episode that really harked by to old school s1 and s2 Buffy. Andrew was also a surprisingly fun character. Xander's injury really pulled at the heartstrings, though that also got thrown aside too quickly. And Nathan Fillion was awesome as the Big Bad.
But the thrown away plot points, the lack of big confrontation with the first, and the overall dunderhead move that helps save the day (something I could have guessed in the first episode), really ruined the final season for me. Even Joss' last episode lacked the wit and drama of what truly made Buffy shine.
I'd never let go of the better moments of s6, but I'm happy to pretend s5 is where Buffy made her ultimate sacrifice and saved the world. For good.
Angel s4 saved itself with a pretty phenomenal last episode. Here's hoping s5 does the same.
Also, has Whedon ever pulled off a great ending? The last two episodes of "Firefly" are pretty weak, though the movie makes up for a bit of that. "Dr. Horrible" has a great ending, but it was all planned out ahead of time. I wonder if "Dollhouse" will prove to live up to the promise of "Epitaph One."