Megan Fox in Transformers 2
In the first movie, Mikaela was a very different leading lady. She was the girl next door, but she had a troubled background. She just wanted to be normal, which is why she dated the jock instead of the guy who was really right for her. She was a complex, interesting character that I couldn't wait to explore in the sequel.
So what does she do in the sequel? SHE NEVER STOPS WHINING!
She was so annoying in T2, that I wanted to strangle her. Yes, she's having relationship problems with Sam, but that's no excuse. She borders on a selfish character. She was cool in the first, but now she's reduced to the girlfriend who just sits around and waits for the robots. And given this is the last time we see her, that's pretty bad.