Preferably, I would choose subtitles over dubbed anime, mainly because the anime would be unedited and raw, rather than the dub being edited to make it suitable for all audiences. I like my anime raw, thank you.
One of the worst dubbed animes I've seen was
DNAngel. I've watched both subbed and dubbed versions of this anime, and they made the dub a little
too accurate on translation, with Daisuke saying "Ms. Riku!" as the equivalent of "Harada-san!" alot. Got a little bit annoying there, but other than that DNAngel is a great anime (though I suggest you read the manga).
Another bad dubbed anime, though it's highly debated in many forums, is Naruto. I still think they Chouji's voice actor was chosen wrongly, and dosen't fit his character. But they edited out the nose bleeds whenever someone does Sexy no Jutsu, and also that they edited out the Sasuke and Naruto kiss, which was REALLY funny. Not only the voice acting has issues, but the anime has been edited to fit younger audiences (and mainly I'm betting that's where their going to get their cash from), and PH dosen't like that. I also did NOT like they way they changed the opening/closing themes.
Anyway, here are some good dubbed anime that I like:
Full Metal Alchemist - I have to agree with you there, Amy-chan. I've watched the subbed and when the dubbed first came to our local anime station, I like the voice actors as well. Although I haven't seen if the anime was edited or not (which I think not), I still consider this as one of my favourite dubbed animes.
Gundam Seed - I know alot of GS fans have been complaining about this, but believe it or not, Gundam Seed had GREAT english voices, in my opinion. I've watched the dub and I'm watching the subbed version of GS. I actually like some of the english voices
better than the japanese voices. For example, Athrun's voice sounded very to somewhat similar to his japanese voice, but I liked his english voice better. And Sei Argyle, his japanese voice has wayy to deep for a 16-year old, and the english voice was perfect, in my opinion. Either way, the Gundam Seed dub was as good as watching a subbed version. (I also LOVE how Matt Hill voiced Kira, he was so much better than Soichiro Hoshi at the crying scenes.

)
One problem though, Gundam Seed was edited with the dub version of it, and PH no likey.