Granted, I am not much of an anime fan (I haven't watched a new one aside from Dragon Ball Super and Sailor Moon Crystal in about 11-12 years, and I honestly don't care to watch anything new ...), but from the ones I have seen, these are my favorite English dubs:
-Cowboy Bebop (duh)
-Trigun
-Noir
-Fruits Basket
When it comes to DBZ, I'm fine with watching it in both languages for the most part. There are parts about the sub that I like more, and there are parts of the dub that I like more. I probably watch the dub more often though.