Which celebrities do you always get mixed up?

You see them everywhere. In movies, on television, the internet, magazines, advertisements, and so on. A few of them are bound to look, act or feel the same. Sometimes to a point where you often get them confused between each other.

“Oh, wasn’t he the guy from that movie? No, that was this guy, but they do look alike.”

So, who do you often mix up? Is it because they look alike, act similar, or another reason? How often do you get them confused?