Also hate smug possessive use of "my" -
"I love my music" whilst clutching a Coldplay CD. Oh your music? I didn't know you were in the band? 
Could of/ would of/ should of...
No.
When people say "No. Just no."
Pacific for specific
Irregardless. Nnoooooo
"I literally died". Yet here you are. Killing me with your shit, unfunny story. The irony.
"Well doh" - said for "yes" but especially said when something is not actually that obvious because I wouldn't have bloody asked otherwise
People who say ASAP as a word rather than letters - "I need that Aysap". Oh fuck off.
Ditto "lol" as a word.
My friend can't say ciabatta and when we go out for lunch orders a "kyabattah". I've started getting the same as her so I can say "two chicken ciabattas, please"
. (in my defense I've told her twice).
When people "turn around" in a conversation (usually to denote an argument or smug one-upmanship)- "so I turned round to her and said, "no Sandra, it's not appropriate to collect the kids from school in your pajamas" pause "then she turned round to me and said "it's not pajamas, it's Jammie's!!""...
I've gone slightly off-piste here... sorry 