Mark's #37: Gnadenlos!
Gnadenlos is what I like to call a "Frankenstein" game - it's made out of parts of other games that somehow mesh to make a wonderful gaming experience. There's the once-around auction for cowpokes (Ra, Modern Art), the payment in specific cards (High Society), the blind bid for actions (Take 6, Raj, Adel Verpflichtet, etc.)... and then, Klaus Teuber put in the "brain" which isn't quite like anything else I've played. The system for paying off your IOU's is original to the game and can make for some serious nail-biting.
Gnadenlos is a 45 minute game with multiple timers that guarantee a quick play. Over the years, I've introduced this to a number of players with great success. Give it a try!