OK, I have a question about the end of season 4 so I'll spoilerize it:
Spoiler:Angel slices Connor in the sports store. How exactly does this bring about Connor's memory loss and new life? Or did Wolfram & Hart arrange this as part of their deal. Maybe I missed something...
Overall, I liked the season a lot, although it did get weaker when they had to write around CC's pregnancy. First half was killer though. Apocalypse Nowish was my favorite.
Spoiler:Or did Wolfram & Hart arrange this as part of their deal. Yes, that's what happened. It's implied by Angel's final exchange with Lilah in what's to become his new office, and it's explicitly stated in season 5.
To answer the question about the end of season four: Spoiler:Connor was given a normal life in exchange for Angel's service to Wolfram and Hart. You'll see more on this -- as it relates to Connor -- in the fifth season.