A few commonly misused words that really bother me are
hugh instead of huge
spade instead of spayed
confirmation instead of conformation
sherbert instead of sherbet
Wal*Mark instead of Wal*Mart
mute for moot
axe instead of ask, really hate that one.
perscription instead of prescription
"past away" instead of passed away
bidness instead of business, omg, drives me really crazy
foilage instead of foliage (my DH says this)
excetera instead of et cetera, and people who abbreviate it ect. instead of etc.
pitcher instead of picture
bafroom instead of bathroom
I mispronounce a few words myself, and no telling how many words I mispronounce that I don't realize I'm saying wrong,

I say height with a TH at the end instead of a T at the end. (who was the idiot who spelled height that way in the beginning, and width with the th at the end is what I'd like to know?!) I also say Q-pons instead of Cou -pons *as in coop*. I try to make myself say coupons, it just sounds weird to me.

Another word I say wrong is dialate instead of dilate, and I also sometimes say reoccur instead of recur, even though I know better. I'm sure there are many more I can't think of right now. Some of these mispronunciations were from my Southern upbringing.
There are a lot more words that really bother me, many are words where people add a "H" along with "W" as in wheather when they mean weather, where when they mean wear, sandwhich instead of sandwich... I see these spelled (pronounced) wrong daily here on the Dis and it really surprises me how often the words are used wrong.