I have friends who are cheap at Tekken, so that series I don't take seriously, and plain just can't stand. KoF, Street Fighter 2, 3, a little of 4, the new MK 9 (played via demo), MK 1-UMK 3, those are the fighting games I like. Two of my recent pickups were SF Anniversary and KoF Neowave PS 2, Neowave is the Japanese version.
Now the ones I really really like, but have never gotten good at, the Samurai Shodown series, and the 2 Last Blade games come to mind. Lots of sword play and weapons to use, very tactical fighting games..