Thus far, I like GX the best, but mostly because it was what was airing on TV when I was into YGO in the 7th grade or so (so 07 or wev). So I remember most of those monsters and stuff the best. That's the reason that the EHeroes are my favorites and all that jazz. I've seen a lot of the original series, though only through battle city, and most of that was when I was really young, and the whole thing flew way over my head. Not a bad show, and I really like that cast of characters, but eh, I think GX is just as good, albeit different. I can't judge 5Ds because I haven't watched it yet, except for the first episode, but from what I saw, it doesn't suit my fancy. I'll likely give it a shot at some point though. As for Zexal, I've only seen a few episodes of this one as well, but from what I've seen I like it better than 5Ds. I think that some of that is that I can relate with Yuma in being a newbie to the game, and picking everything up, instead of leaving one of the main characters friends to that job like in previous seasons (Joey, Syrus, idk was there one in 5ds?). And then of course, there's season 0. That's the only one that I've watched all the way through :3 I loved it! I liked how they had the series going (using several games) before it got cancelled. That one's technically my favorite, though I don't group it with the other yugioh's just because it's pretty much the same characters in a different show.