I'd deffo have to say season one before love triangles. Being held up at gunpoint, and pregnancy scares. She was so cute in season one. Love ya Brenda babe.
I voted season 3, I liked her in all the seasons but season 3 sticks out more for me. Probably because of her trip to Paris and her accent she uses with Rick in Paris.
I chose season 2 because that was when her and Dylan were there strongest and she was a little more grown up and had lost some of that immaturity from the beginning of the 1rst season.
I haven't seen all of season 3 but the episodes I have seen I think that its also worth mentioning because you see more of a range in her personality as well as Shannen's great acting abilities.