My biggest complaint is about the lack of balance. I know the show is centered around Elena and Stefan and to a certain extent, Damon, but why hire so many awesome people if you're not going to utilize your cast?
I'm no Elena fan, but imagine how much of a mind warp it would be to find out your boyfriend is a vampire...and that he has been lying to you? I mean, she was understanding as she could be and she said she would not reveal his secret, but she had every right to break up with him.
And, the one thing I do like about Elena is her hatred of all things Vicki.