Inuyasha must be one of the worst dubs I've seen. Kagome's voice is so irritating-- it makes me want to throw something at the TV to get her to shutup. Then there's Kagura: Helloooo- you're trying to kill these people, not seduce them! And Kouga sounds like he's on drugs or something, not to mention all the other wolf demons' voices are kinda squeeky. Jaken sounds like a smurf O.o (wait... maybe that's not too ooc) But I have to admit that Rin's and Sessho-maru's voices are well-cast. (When Naraku says Kanna's name, he sounds like he has some sort of speech impediment and can't say it right-- is that how her name is supposed to be pronounced?)
But Princess Mononoke was a great dub. Love that movie :) .Hack//Sign has some really good voice actors, too.
Hopefully I haven't been too much of a critic... or offended anyone....