Discworld Diceless. A mash-up of the GURPS Discworld and Amber Diceless roleplaying games that I had tinkered with sometime before the turn of the millenium.

A couple of quick games for those nights when no one feels like running a full campaign.
Dungeon Dealer. A game for 3-4 players. Requires only a standard deck of cards.
Chess Dice. A game for 2 players. Requires a chess board and two sets of 32 dice.