Starcraft Ghost for the Gamecube. That game looked pretty hot, and it had a female lead (always a plus). So much work and then they cancel it?
Runner up: Half Life for the Dreamcast. The game was complete. It even had a perfect score review in Gamepro magazine. For some reason, the game didn't get released!! I never did play a Half Life game until I got my hands on The Orange Box a couple of years ago. This was a dis-service to console gamers. By the time a PS2 port was released, it was buried among other huge PS2 games.
Starfox 2 gets an honorable mention since elements of it eventually became Starfox 64. Kameo 2, too. I loved the first one.








