Soul Calibur. The game where girls look like balloon animals (for those wondering, I ALWAYS play Taki, no matter which game I'm playing... though I do like SC2's ability to play as Link, on the GC version...). This game is frighteningly simple and easy, compared to something like Virtua Fighter, or the amazing, underrated classic Tobal No. 2 (not No. 1... No. 2, which is a masterpiece)
I like these games okay; fast, good looking, insane... but man, they just don't match a 2D fighter. I just don't get much satisfaction. To be honest, the best 3D fighters I've ever played are Bushido Blade 1 and 2.