Marvel Super Heroes, Waku Waku 7, Tech Romance, Megaman 2: the power fighters (all 3 story modes, but save Roll is the one i never lose at), Power Instinct: Matrimelee, Marvel vs Capcom 2, Marvel Super Heroes vs Street Fighter, Rival Schools.
Basically Fighting games, but honorable mentions include reaching Stage 5 with one credit in Metal Slug X, reaching level 4 in Metal Slug 3 (without losing a life) and reaching the Magician in one credit on The House of the Dead.