Neon Genesis Evangelion. Dub or subtitles?

[Cless]

Okay, so my Evangelion perfect collection arrives in the post. I can't wait to get my teeth into this series! Problem is, I really want to ensure that I get the best viewing experience, and I don't know whether to watch the English dub, or the Japenese subtitled version. I always get this problem when I buy anime!

So my questions for you are:
-Which version do you personally prefer?
and
-Is the English dubbing of a good quality?

Thanks for reading.