I prefer dubbed, but only if its good i.e. Cowboy Bebop, Hellsing (Crispin Freeman has the voice I thought Alucard would have before I saw the anime), etc. Unfortunately most english dubs are downright atrocious ergo i watch a lot of subbed. Although its funny sometimes when the subbing is so bad i cant watch it all.
Furthermore, i cant see how any not japanese fluent person could get more out of hearing a japanese voice and subs compared to an english voice, even if its bad. example: what does a british accent in japanese sound like? oh you know whats better? having a japanese person sing in german. its bad, its really bad.
although i must say it is fun to listen to japanese during comic relief bits.