2. Jennifer Parker - Back to the Future Part II
Granted, we don't really ever see that much of Jennifer Parker in the original
Back to the Future movie, and though she's played by two separate actresses over the course of the trilogy - Claudia Wells and Elizabeth Shue - the two versions of this character are so at odds with one another, it's angered me ever since I was a person capable of being angered by things like this. That's to say, Jennifer Parker gets a major personality overhaul in the space of a few minutes. It's insane. In the original flick, Jennifer exists mainly as a prop: she's Marty McFly's super hot, super cool girlfriend - so cool, in fact, "The Power of Love" by Huey Lewis and the News plays when he kisses her. Claudia Wells, brief though her role is, pulls this off brilliantly. But when Wells couldn't return for
Back to the Future Part II, she was replaced by Elizabeth Shue, who plays the character
totally different. Instead of cool and confident, the new Jennifer is irritating and dumb - so much so, that you secretly want Marty to abandon her in the future. Seriously, what happened here?