ermm..
side pocket on the megadrive..
pocket gals arcade (if emulated on gp, side pocket hardware)
'the billiards' arcade (if emulated, should be it's on scramble hardware)
lunar pool nes
that's about it..
i reccomend billiard acadamy real break arcade, that will never run on gp32 tho.
Archer Mcleans pool has 9-ball, should be available on the ST and a few other formats... IIRC the GBA version even works slowly on one of the GBA emulators for GP32.
I was thinking about good Pool games the other day after I had a quick go of Side Pocket......it'd be awesome if someone could port the old Team 17 game 'Arcade Pool', that game was insanely good.