NGE is much better in Japanese. The American dub is hammy, whiny, and generally over the top and tends to leave people with a negative impression of the show.
Most anime are better in Japanese. The only high profile examples of anime that work noticeably better in English I can think of are Cowboy Bebop, FLCL, Black Lagoon, Gurren Lagann and The Girl Who Leapt Through Time for some reason. Maybe there are other examples, but in the end anime dubbing in English is far more of a niche thing than anime dubbing in Japanese is, so the cream of English voice actors and recording engineers and what have you often wind up in local productions.
Plenty of English anime dubs are perfectly acceptable, even if they're not as good as the original Japanese dubs. Neon Genesis Evangelion is not one of those shows.