ZERO! and I found it on the blog, "I Speak Math" written by Julie Reulbach.
The game is basically blackjack with the goal being to get 0, not 21. The red cards are negative and the black cards are positive. The student with the number closest to 0 when the cards are added is the winner of the round. Students calculate the absolute value of each of their round totals, then at the end of the game, they add up the absolute value column. The student with the number closest to zero, is the winner of the game. This sounds like a blast! I think my kiddos will love it and it reinforces addition of integers and absolute value all in one game!!
There is a link above to Julie's explanation of the game at "I Speak Math". Her direction and score sheets are there as well. I don't subscribe to Scribd, so I recreated the direction sheet and score sheet myself. It is basically what Julie has, but I added learning goals, supplies, an example on the score sheet, and a reminder to turn it in for credit. It is below if you'd like it.