Funimation dubs are infinitely better than the abortive 4Kids ones; no wonder they filed for bankruptcy. Even then, a lot of the voice actors are people no one ever heard of, the only notable exception are Studio Ghibli, as they hire real actors. But Naruto and One Piece are better in Japanese IMHO, but that may be due to the fact that I have a pretty grasp on the language.
The other thing is why can't they translate the title theme songs in English, instead of creating new, unfitting songs (*cough* Digimon series 1-3, Dragonball Z *cough*) that often suck? Sorry, I had something caught in my throat.
Another issue is unnecessary censorship, such changing Yen to Dollars, making bomb-tossing enemies throw oranges instead, or the best one, a digimon who kidnaps a child and forces her to make milkshakes (edited from making sake into shakes). Some things are better left the way they were. But theme songs are the worst offender.
I could go on and on, but I won't. I digress, not ALL dubbing sucks.