Heavy Rain. The voice acting was terrible on various occasions, especially the angry-and-always-screaming-and-flipping-out-for-no-reason police chief, as well as the bald dude who you fight with Scott Shelby in the prostitute's room. It didn't necessarily "break" the game for me, but it definitely made it less enjoyable.
Killzone 3 is actually another one. I thought the voice acting was pretty bad, and it ruined a lot of the experience for me. I didn't even finish the game, and that rarely happens. But maybe it was a good thing. Normally I get games primarily for the campaign; but, since I was so disinterested in the campaign of KZ3, it pushed me more towards the multiplayer. Have always found fps multiplayer boring, but KZ3's multiplayer is fantastic. I still like campaigns more than I like multiplayer; so I hope GG finds quality voice actors in the future. They need to take some lessons from Naughty Dog;)
