I love the S4 is a good season has its flaws and weaknesses but it has a solid story that tries to connect with the rest of the seasons. It was great that the S4 left a obvious path to its end in the S5. The villain of this season gives meaning to the rest of the seasons, I love how most of the characters have grown, they are no longer the kids of S1, S4 is a season of nostalgia, memories and deja vu.
My second place is S1 is the season that started it all, the story is interesting. I was very intrigued to find out what was going on. (I had read a synapse of what the show was about, but had no idea what would happen, it's an excellent season and has a strong story.)
