I played all of these 'cept the dreamcast/PC ones. Though I did play Grim Fandango at a friends house and I loved Skullmonkeys, the sequel to the Neverhood.
The demo was indeed very fun, however, the fact that it's only 6 hours or so might put me off getting it just yet. It's for the same reason I haven't bought CoD:WaW yet. I only have so much money, and I want a game that's going to last.