2 more games to AVOId if you are stressed : Adventures of Shuggy starting the Gallery. Super Meat Boy, as a whole. 1000 Amps quickly annoying, And Sherlock Holmes, Mystery of the Mummy just because this last one is plain horrible.

Lol. But yeah, seriously, first I tried easy difficulty because I feared it would be one of those frustrating unforgiving oldschool games that you have to learn the hard way. I didn't understand what the challenge was, though - turns out that the game is basically about running people over until you get bored and decide to finish the "race" by bashing all your opponents or passing all checkpoints. The game is a pure stress reliever, especially when people die in silly circumstances (like once I missed a pedestrian, hit a pole in the process, when I had already given up on him the pole fell right on his head - I watched the scene in replay dozens of times, laughing my balls off).

Starting a new game in Fallout: New Vegas, making an older (age slider) character with a magnificent mustache, putting everything into explosives and then tossing dynamites at bandits and wildlife has a most nerve calming effect.

Ha! It's good to hear that. Trial and error is the last thing I want to do when I'm strung out.

I kind of wish there was a way for me to try before I buy, but if there is a good enough offer I might throw some money at it.

WoW

My favorite game of all time is incredibly relaxing: Endless Ocean: Blue World. Only bad thing about it is the shitty music (they should have made all the songs ambient, or if they wanted to stick to their chosen genre, at least have someone good like Mary O'Hara). Flower, Journey, A Boy and his Blob, and Kirby's Epic Yarn are also effective.

For me, puzzle games like World of Goo, Spacechem, Minesweeper or Sudoku work very well.. They usually keep the problems thats stressing me off my mind..

Hmm, how about Nation Red
It's all about fighting endless hordes of zombies.
That game is a lot of fun.

Casual games which you can zone out on. My favourites are Faerie Solitaire and Peggle Deluxe.

I find Civilization IV to be extremely relaxing, especially in multiplayer with friends.

Don't play anything with checkpoint saves.
Been there. done that, almost lost keyboard and window.
A good hack-n-slash like Torchlight (I or II) where you can't really lose is good.

But I love this idea:

The last (secret) level of Immortal Defense.

Euro Truck Simulator 2. This game is amazing in terms of zen factor. Just play some mellow road music in the background and get to transporting yoghurt from Zurich to Prague. AND BEYOND.

It's also a good, finished and addictive game, incidentally.

sorry, nevermind.