With regard to "could care less": You'd either have to say "as if
I could care less" or at the very least say "I
could care less!" with the same overemphasised sarcastic tone as "I
should be so lucky!" for it to make sense. Sadly, every time I've heard anyone say it they've done so with the same phrasing and tone as if they had actually said "I couldn't
care less". This is an easy mistake to make if you care less about getting your mesage across than you do about being ironic and offhand. In fact, if you think about it for long enough your brain will go into an endless irony loop. Within a matter of seconds a quantum singularity will form between your ears and your head will implode. LOL EPIC FAILZ!1!!!11
"Proactive": thank you N7SC. It makes me want to punch things. There is no situation where that abomination is preferable to "active". It is redundant BS. It used to be that everyone except insecure middle management types thought this, but here we are years later and everyone's using it. STOP IT RIGHT NOW!
"Cheap at half the price" (instead of "cheap at twice the price") is silly to anyone with a basic grasp of maths, but people say it all the time.
"Center around" (instead of "center on") is wrong but probably considered too pedantic to mention.
"Invalid", when used instead of "incorrect"... It won't annoy most people, but anyone who programs even semi-regularly should despise it as much as I do, because it's a mistake generally made by those who should know better. e.g. "invalid password" instead of "incorrect password".
I actually quite like "fail" and "win". Massive overuse has created a backlash, but fashion will move on.
Oh yeah, I almost forgot... Like, people who, like, say "like", like every second word? Listening to them, like, talk and stuff, like, totally makes me dream of, like, gouging my eyes out with a broken light bulb.