Currently Mame will run anything under 22mb...
PERSONALLY
Ive tested
Marvel vs Capcom
Msh vs SF
Xmen vs SF
SFA 3
SFA 2
SFA 1 - Warriors Dreams
-- Those didnt run
To sum it all up, all the later roms that are CPS 2 didnt work
Neo geo
KoF 95 ran,
KoF 96 - Memory problem so it didntA
Metal Slug Ran, 2 didnt, X, didnt
and dont even think about 4
Hopefully in the Next release they'll be able to run more CPS2 roms
Evo Tek