Seasons 1 and 2 were partially ruined by silly sidestorylines of Kim Bauer's idiotic adventures. Not gonna go in details why it was so retarded, but It annoyed me how they used good episode time by filling it with that irrelevant crap which mainly was just an annoyance because of Kim's stupidity and ability to get in trouble. Glad they kinda got rid of that garbage. Also, speaking of Kim and ridding stuff - glad they got rid of Chase too. IMO they tried to make him too much like Jack Bauer v2 in more handsome looks. He and Kim made a perfect couple as both were extremely annoying,

As for my favourite seasons...it's pretty hard to rate them. Ever one of them has their ups and good moments, so I rather not to put them in order. I try to see them as one whole.