Virtua Fighter gets my vote, closely followed by Tekken. I play Tekken more, largely because it's fifth iteration is more recent, and generally a bit more fun, but Virtua Fighter is the better game.
Soul Calibur I find a bit lifeless, and Mortal Kombat is a pathetic excuse for a fighter. I'm not a fan of 2D fighters, so that rules all those out. Including the ones that look 3D, but fight 2D style.
Bloody Roar I have a place in my heart for, but will gladly accept it really can't compete with most other fighters.