Ow, my ears!

These mispronunciations kill me. (Hint: if you're not sure of the pronunciation, choose another word. That's why I avoid "banal"...I really should look that pronunciation up in my favorite Big Book of Beastly Mispronunciations.)

empire waistline.
Don't say "umpire waistline." This fashion style has little to do with baseball officiating.
Say ahm-PEER (French pronunication) waistline.

memento.
Don't say "MO-men-to." Here's a hint: Think "remember" or "reminisce." Don't think "moment," or it's all over. (And please don't go saying "reMOnisce" either.)
Say mem-MEN-toe.

Moscow.
Don't say "Mos-cow." There's no "cow" in Moscow.
Say Mos-coe.

Neanderthal.
Don't say "Nee-AN-der-thal." Lest you be thought one, the "h" in "thal" is silent (German pronunciation).
Say Nee-AN-der-tall.

nuclear.
Don't say "NUKE-you-lar." Thank you, Still President Bush, for this legacy.
Say NEW-clee-ar.

often.
Don't say"OFF-ten." Do you say the "t" in "listen" and "soften"? The "t" is silent.
Say OFF-en.

would have, should have
Don't say (or write) "would of, should of." These phrases don't exist.
Use "would have" or "should have."
Note: This is also flat wrong: "If I would have known...".
It's "If I had known...".
A correct use of "would have" is: "I would have called you, if you had let me know. But probably not, given your careless pronunciation."