If you liked the Spiral anime, the Anime-Planet community thinks you'd like:
Yugi Mutou was a boy who was constantly bullied – until one day he managed to put together an ancient and mysterious puzzle that no one has been able to solve for two hundred years. Now, whenever Yugi's friends are threatened, a strange transformation occurs, and Yugi seems to become an entirely different person. This transformed Yugi is a master of games, and uses these spontaneously-invented games to trap and to punish the bad guys. At the end of each game, his opponent appears to suffer a painful death; but it is soon revealed that this was all in their minds – or was it?
While the original Yu-Gi-Oh! is entirely different than the card game series, it feels close to Spiral, since it doesn't have much to do with the card game yet, which makes it a lot more serious.
Both series are about smart games of life and death, and they have a specific feeling to it, which is rarely to find anywhere.
If you like the atmosphere in one, you'll probably like the other one as well.