Honestly, I think all the hate for English dubs is pretty stupid, and I'm both a long time anime fan and someone who knows Japanese to the point where I can almost go without subs (depending on the content of course). There was a time when a LOT of dubbing was pretty awful, mostly I'd say in the 90s when they were trying to edit a lot of anime to make it more G rated for kids. And I don't mean editing as in just changing meanings around, but as in they would actually cut up and doctor up episodes. Some shows had entire episodes that would never be shown, some had orders changed around, some were combined, etc. If you knew this was going on, it was pretty easy to hate any anime done in English. Bad voice acting was just the cherry on the cake.
Nowadays though English dubs have come a LONG way. Funimation's series have consistently put out VERY good dubs throughout the past several years and there are a lot of English voice overs that have gone on to surpass the Japanese originals. So really, I think there are a lot of people who hate on the dubs just for hating on the dubs. Now, if you just prefer the Japanese voices, then that's your thing. But to act as if most dubs are still crap is pretty shallow. Oh, and to the people who mention that there are sometimes things lost in translation, that happens regardless. You can't blame them for changing references when translating for a culture that would never understand the references in the first place. A straight copy/paste translation is NOT a good translation. In fact that is where you will have the most meaning lost. A really good translation comes when you have people who not only understand the cultural references/subtexts but also are able to figure something comparable in the language they're going to. That's a good dub job.
As for me personally, it really depends on both the show's content/context, AND the quality of the voice work. Things that are meant to take place in the west with western characters and names. Those are the ones that I DEFINITELY want to watch in English. It's not that the Japanese voice overs are bad, but it just doesn't fit well with the context, and unfortunately the Japanese butcher our language just as badly as we do theirs. I hate hearing them try to struggle to say a western name right and there are vowel sounds that shouldn't be there. It's not their fault, it's just that there are so many sounds in the English language that aren't in Japanese, so they just do their best.
Hellsing Ultimate is a perfect example. This show is not only about vampires, but it literally takes place in England and everyone in the show is European. I mean hell, they have Nazis! In Japanese, not only do I have to listen to them try to use English names and phrases accurately, but now they've thrown German in to the mix. It just pulls me out of the show. The dub on the other hand is well done. It flows better, the English fits in the context and they're even able to have accurate accents (well most). A few other notable mentions that I think are better in English would be Panty and Stocking, Fullmetal Alchemist (either one), and Code Geass. On the other hand, I think shows like Lucky Star, Azumanga Daioh, and Sailor Moon are more fun in Japanese. Then there are those that I can go either way on such as Baka and Test.