KOF '98 UM: https://www.gog.com/game/the_king_of_fighters_98_ultimate_match_final_edition
KOF 2k2 UM: https://www.gog.com/game/the_king_of_fighters_2002_unlimited_match
These are the same games that have been available on steam just DRM Free. Also judging from the leader boards, the games...