In my opinion, The Melancholy of Haruhi Suzumiya has a good dub, it has some of the most famous voice actors in the Japanese version, but I just preferred the English.
Persona 4:The Animation- Johnny Yong Bosch AND Yuri Lowenthal.... pure genius and comedy to follow. The rest of the voice cast are golden too and they did a good job putting in english 'slang' terms and making it flow really well.
I don't watch a lot of dub anime because I usually prefer watching it in the original Japanese but I also really like the dub versions of:
Eden of the East- kind of like P4, they did a good job making the english sound natural and flowed really well
Hetalia- Accents are awesome!
Fruits Basket- I first watched in English so Japanese sounds weird when I watch the anime now
Dragon Ball Z - (I can't get into the Japanese voices)
Kodocha- Which is a shame that I like the English voices because only season 1 was dubbed. So I had to watch the segundo season with the Japanese voices.