1. Tie between Hush/Restless. Hush was just plain creepy as hell. And I love the whole fairytale villains thing. As for Restless, the Cheese Man. Nuff said.
2. A New Man. The scene with Giles trying to communicate with Xander just cracks me up every time, and I love the almost goofy music that plays. And Giles chasing Maggie just about made the episode.
3. Something Blue. Well, for one thing, they play blink-182. Yes, I chose an episode for my favourite because they play a song that I like. ._. But that's obviously not the only reason... I like the whole alternate universe kind of thing that happened, a bit like Tabula Rasa.
4. Tie between Where the Wild Things are and Fear, Itself. I love creepy episodes, and these two were really great.
5. This Year's Girl/ Who Are You. I think it was a great way to bring Faith back into play, although eliminating her quickly. I love the part where Faith (in Buffy's body) beats up her own body, telling it that it's useless and whatnot. You can really tell how she's been suffering.
The Yoko Factor was also awesome because of Giles's drunk scene. XD
As for ones I didn't like, I dunno if I could name one specifically... Superstar was meh, Doomed as well... It was weird just to have an apocalypse in the middle of the season. Living Conditions also wasn't so great. I can't put my finger on one thing, but I just didn't like it that much.