Hows about Garou and KOF 98 on XBLA?
What SNK DID bother to keep is neo-geo mode. You can play KOF 98 as it was on the AES so you get 2 games for one, however regular 98 does not get it's own set of achivements.
If you haven't picked up the superior PS2 version yet here's what Ultimate match adds to the table. Eiji, Kasumi, Geese, Krauser, Mr big, Orochi, Goenitz, Riot blood Leona and Riot blood Iori. Also if you don't want to fight Rugal you don't have to getting a certian number of DM finishes nets you a battle with either Goenitz or Orochi while both are hard battles it's not nearly as bad as if you have to face Rugal. Beating these bosses unlocks them.
Online is exactly the same as Garou and unlike Garou I have had one weird laggy match This is a problem for achivement whores if the game is laggy online as half the achivements are online based.
If you want KOF 98 on line here it is. If you want the best most complete version of KOF 98 get it on PS2.