Three pronunciations I dislike, especially when they pop out of my very own mouth (and before anyone gets mad, I know some of these are regional pronunciations and are fine elsewhere, but not where I have always lived):

Jewlery (or jewlry) for jewelry
Nuculer for nuclear
Relator for realtor

And I also get mad at myself when I use an all-too-frequent local way of pronouncing words by putting an r-sound where it doesn't belong or leaving it out where it does. Examples are the names Pauler instead of Paula and Heatha instead of Heather.