Season 2 was poor because of the writers strike. They had no freaking clue what to do at all.
Damn I want to watch FNL again. I've seen S1 almost four times through (and the rest only once) and it's still amazing. I really need to see Season 5 again though. I was just amazed at how much it succeeded my expectations.
Imo
1 > 5 > 3 > 4 >>>>>>>>........>>>>>>>>> 2
4 was very good though.