Gauntlet xbox, 19.99 at Sam Goody
 

Mediocre reviews, but I imagine it will be fun in multiplayer at least.

Yes, it is a very fun game. Myself and three friends spent weeks on end playing through it. We finished the regular game, but didn't unlock all of the levels. My friend paid $50 for it and it was completely worth it, so $20 is a steal.