Samurai Shodown II
The second game in SNK's Samurai Shodown line is widely regarded as the best of the series.
Art of Fighting
Art of Fighting brought several key new features to the fighting game scene; most notably a "spirit" bar that limited the number of special moves you could perform.
Fatal Fury 2
Though the actual gameplay was similar to its predecessor, Fatal Fury 2 added a number of playable fighters to the roster.