What Games are You Addicted To?

Anonymous Coward from Gamers Anonymous asks: "Recently I have found myself highly addicted to Freecell, as I cannot go near a computer without just playing a quick game or two, I even have one going at the moment. In the past I have also had problems with Minesweeper and Tetris, both of which I overcame when I had to delete them around exam time. Is there anyone else out there with this problem, I can imagine it would be quite common. What are the most addictive games out there? Is there a support group?" I don't know about PC games, but I've been playing an awful lot of Frequency on the PS2. I just can't seem to help myself even though the game can be frustrating as hell at times. Anyone else have a game that, once under the skin, you can't get enough of it?