Hmmm, okay, here's my opinion:
I think DP is the best series, then the Neo series, then the E-Card series. DP is the best in my eyes, no because it's OMG POWERRRFUL, because that's not something great a bout the series itself - Anybody could supe up pokemon cards, which is what Nintendo's done. I like it because decks these days have more strategy than decks in the old days. There are more techs to work with, etc. which brings in skill for fast set-up and whatnot. The old sets in terms of art and card set-up... Were probably better, IMO. Except the Lv X's, those have fantastic artwork. And the E-Card sets, were, uh, just really cool.