I know I have a few, and commit some that drive others batty....

But the one that drove me nearly insane and I finally had to have a discussion with an English major and correct her misuse on was "ideal". She was using this as an apporpriate substitue of "idea". For example, "I have an ideal on how we can solve the most recent problem."

Mine that I've been corrected on are unthaw and another negated word that escapes me at the moment.

One my mom says that now drives me up a wall is prit'near. It's a midwestern thing and makes me crawl under a rock when I hear it.