coup de grâce - should be 'coo da grass', I say 'coo da gra'
If I manage to get the short 'a' sound right, I'll spoil it by underpronouncing the 's' sound at the end. (I'm from the south of England, so I pronounce words like grass and last with a long 'a' -you know, properly- but a lot of French words have short 'a' sounds) Coup de gras would sound like that, but that would mean 'blow of fat'.
Warren Buffett
I pronounce his last name Buff-ay, not Buff-ett. I went to business school and gave an entire presentation about him and his company, mispronouncing his last name every time. No-one corrected me until it was over.