I recently got introduced to Carrom which is a sort of shuffleboard version of pool which is a traditional game from india/pakistan.
The board is square with a hole in each corner and the idea is to pot all your discs and the red before the other player does.
It's a lot of fun and much harder than you would imagine at first.
There's a good implementation on miniclip called carrom pool but I went the whole hog and blew £45 on a board from Amazon. It's huge (32" square) but so much fun.