Season 1 was good. Season 2 was great. Season 3 was good. Season 4 is was absolute trash. It was one of the worst seasons of any series I have watched. Season 5 is good so far. But then I rewatched s1-s3, which I stated were good, but compared to them s5 is garbage as well.
I do suggest watching the first three seasons. However, s4 and s5 I strongly advise you do not watch UNLESS you are a mature, politically correct, gay 7 year old.