I found S2 overall more frustrating than S1, mostly because the good parts were so good! but the bad parts were SO BAD. My old roommate made a supercut of Season 2 that cut out pretty much all the Republic City parts and everything terrible related to Bolin/Eska and Bolin/Ginger, just so she could make our other roommate watch it without having to relive the parts that made us seethe in rage.

(SEASON THREE OVERALL IS SO GREAT THOUGH. I think my final ranking goes:
final two minutes of season four
season three
the rest of season four
those two Wan episodes and everything in about Jinora in season two
season one
the rest of season two)