Forgive me for joining in late, but there are so many that irritate me. The one that comes to mind right now is the word salmon. Usually people I don't care for pronounce it sal-mon, pronouncing the "l" which should be silent.

I see and hear so often, even read it in books by well known writers, where they say for example "Go jump IN the car" , and they should say , "Go jump INTO the car".
Because, how high can one jump in a car?
I feel like telling people who talk this way to "Go jump into the lake, and then jump in the lake"