"After the Fall", hands down.
In all honesty, S8 is a jumbled mess. It's way, WAY to big, the characters make crazy decisions that are never followed up on (Buffy robs banks now?), shock value is used to cover thin storylines (look, Dawn's a giant! Now she's a centaur!) and not many of them make much sense in a linear fashion. I can't remember the name of the arc, but Buffy in Nepal and the subsequent invasion are some of the most eye-roll worthy comics I've ever read. They make zero sense, and make Buffy seem like a crazy person. Spike had virtually no role; he just shows up late in the game, somehow knows absolutely everything and then smokes a lot of cigarettes. It's never explained (that I can remember) how Angel suddenly has all these extensive contacts in the American military who trust him so much they're ready and willing to invade other countries and just hope no one notices. It's never explained why Buffy and Angel need Superman powers. There's just so, SO much of S8 that's just garbage.
And Twilight? Aside from simply not enjoying it character wise, is ridiculous. It shouldn't take me coming on here and reading extensive explanations of just what the hell Twilight was and what it was doing to follow the story. That's stupid.
By contrast, I thought AtF felt like the show. It was big too, yeah, but the size of it didn't subjugate the plot or the characters, which happened badly in S8. I thought all the characters fit, and the dialogue worked. Spike had a great niche for most of the run, there were awesome twists (Angel's humanity, Spike secretly helping L.A. citizens when you think he's not), Connor was excellent. Yeah, I thought AtF was great.
S8 just makes no sense.