I've just been playing an addictive game. It's called Deal Or No Deal and it's based on the TV show of the same name.

Deal Or No Deal works like this. You choose a suitcase at the beginning, which has cash in it, but you don't know how much. Then you open other suitcases and amounts are checked off at the side. Every so often the banker makes you an offer which you can accept or decline, obviously trying to hold out for as much money as possible.

The game is free. It's from Winzy which allows you to earn credits for searching and play online games. Deal Or No Deal has no prizes, but if you like it you can play the same game for prizes at Winzy. The prize winning version is called Secret Suitcase.