I grew up watching dubs like Yu Yu Hakusho and Cowboy Bebop, both of which are great. I tried to go back and watch subbed and couldn't do it. Maybe it's just nostalgia. Either way, here is my list of great dubs (I'm not saying these are necessarily better than the Japanese dubs, just that the English dub was also good):
Baccano! (It's set in America, so it just makes sense to watch this in English, imo. Also, Micheal J. Tatum as Isaac is fantastic).
Steins;Gate (Again, Michael J. Tatum is great, as is the rest of the cast).
Konosuba (I found the dub to be way more entertaining than the sub in this case).
Toradora (I never watched subbed, but I really love the dub).
Future Diary (Mainly because of all the expletives, which I prefer to hear in my native language).
Both Re:Zero and Shield Hero deserve honorable mentions here. Although I prefer the sub for both, each are admirable attempts when it comes to the English dub).