With many systems there is a "signature game" like super mario for the NES. Tekken3, FF7, and whatever for PSX, and so forth...
What would you say was the game to have for the Turbografx 16?
Note: I have one coming in the mail.
Bomberman.
Bomberman '93 for the TG16 remains the best party game of all time in my opinion.
Bonk and Splatterhouse are both excellent games as well.
I think the three games that have already been mentioned sum it all up for the TG16.
My favorites are:
Keith Courage
All 3 Bonks (the 3rd one will cost you a fortune)
Alien Cruch
Devil's Crush
Sinistron (my favorite)
Dragon Power
Dragons Curse
Neutopia
Neutopia II
Keith Courage was the US pack in game for the TG16 so it's pretty much the signature game of the system. With popularity the Bonks would be a close second.