I have never played any of these, but a few look cool. Are any of these cool? Are any worth the money to buy them? How many "bits" does the system have?
IGS has a slew of minor hits (similar to SNK)... there are a ton of gems on that system. Bee Storm, Martial Masters, the Knights of Valour games, and as stated above... Demon Front, among others. I haven't fallen down the path of PGM yet, but I've been tempted many times. Probably the next system I'll start buying games for, eventually.
Martial Masters didn't really do it for me. But Demon Front is pretty awesome. I never got to play Gladiator before selling all my PGM stuff. Been tempted to grab the PCB version though.
Demon Front and Martial Masters are both excellent games. Knights of Valour series is great if you're into sidescrolling beat-em ups in the vein of Capcom's Dungeons & Dragons CPS-2 games. For some reason I could not get into The Gladiator (aka Road of the Sword), it felt very bland and uninspired to me, at least compared to KoV series. Oriental Legends, while it plays quite decently, unfortunately sports some of the ugliest graphics on the system - if you're used to the graphical standards set by the afforementioned games, you're definitely in for a shock ...