Yes, Keanu in Dracula. If I'd been the director, after shooting the first seen where he speaks I'd've said, "Cut! This ain't gonna work out, sorry Keanu."
It's so dumb that they cast him because it ruined the whole movie for many people I've talked to. He was also hilarious in Dangerous Liasons.
Also Jodie Foster in Silence of the Lambs nearly ruined it for me. GAWD!
also Kevin Costner in 13 days. It wasn't super bad, but it ended up sounding more like a cartoon, like Mayor Quimby on the Simpsons.
and holy BROther, Tom Hanks is overrated anyway, but any movie where he attempts an accent is unwatchable to me.
uke:
And I know Natalie Portman does okay, but something about her British accent is very embarrassing like kids play-pretending or a junior high play, to me.
Which also reminds me of the first few scenes in Star Wars where Princess Leia is inexplicably doing a half-assed accent which she later drops. It's like she was trying to impress Vader and Tarkin.