I loved how the 1990 Neo Geo could compete with much later arcade systems. I think the best looking Neo Geo games beat out the best CPS 2 games (1993 tech). And the sprite animation in some of the later fighting games wasn't even that far behind Street Fighter 3 (1996 CPS 3 tech). Not as good, of course not, but for 6 years older it's frighteningly close.
Mark of the Wolves, Last Blade 2, Pulstar, and of course the Metal Slug games all looking good even today (only the low resolution hurts them). Even the Art of Fighting games had huge sprites. And, although crappy gameplay-wise, SVC Chaos had some decent graphics at times. Mainly the fact that it actually imported Hugo from Street Fighter 3 in almost all his CPS 3 glory.
Female Hugo too...
http://rq87.flyingomelette.com/FF/SVC/10.png
The best?
Garou: Mark of the Wolves
Just a great fighter, with great graphics and even good music. Each character was simply fun to play as. In high level play it can be annoying to get caught in infitite combos from break and feint moves, but on a casual or high-casual level it is quite fun and fair.