[JJXB]

i'd say test the waters with cps1 and older games first. that way you have a solid idea of what works before you go onto testing the cps2/neogeo games on there.
a couple of cps1 games to try first:
Final Fight
Megaman: The Power Battle.
if you want to try cps2 games go for:
Marvel Super Heroes
Street Fighter Alpha 3
Super Puzzle Fighter 2
NeoGeo:
Metal Slug: Super Vehicle 001
Shock Troopers 2
Garou: Mark of the wolves.

this is from my experience of testing so i know what my computer is capable of.