We could so be friends!

Pokémon games or similar, like Zanzarah for PC.

Also, as other people said, turn-based strategy games, sims and graphical adventures are always nice if you want some relax.

Civ5, Tropico, Poker Night, Zanzarah, Stronghold, King's Bounty, Spore; these are games I usually play at night if I need to relax before bedtime. I would also suggest The Void, but you'll probably need the "easy patch" to survive by playing with your brain turned off.

MoO2

I think Gravity Bombs was the most relaxing game I've ever played. Check it out, it's freeware.

Puzzle Quest / Bejeweled

Audiosurf on the easy level = listen to your favorite music with some relaxing gameplay.

Dear Esther. It's like going for a relaxing walk. Sure, you'll be seeing the same sights over and over again, but the same applies to walking around the city and I haven't got bored of that yet.

Some nice casual titles from PopCap like Plants vs Zombies or Bejeweled, some old games i know in and out to prevent my brain from thinking too much, mostly MoO 2 or Phantasie 3, some puzzle games like Sudoku and so on and well something really really relaxing is Osmos, wonder that noone mentioned it yet. Some say its boring, but i love it every now and then ;)

I find a lot of tablet games relaxing, perhaps because of the more minimal controls and simpler design of a lot of them. The </span> series is very soothing, even when the puzzles are infuriating. Some of the world building Match-3 games are also relaxing, with my top pick there being [url=https://play.google.com/store/apps/details?id=com.the10tons.heroesofkalevala]Heroes Of Kalevala. And the abstract strategy game rymdkapsel is lovely until the attack waves begin in earnest.

On the PC, older abstract games tend to be more peaceful for me. Games like and the [url=http://www.mobygames.com/game-group/freescape-games]Freescape games.

Myst, as long as you're not trying to solve the most difficult puzzles.

Reading through this thread, I realized I don't have a particular game that I play to relax. To me, gaming is relaxing time, so even if a game is difficult (I'm currently looking at you, Dragon Age: Origins), I consider myself to be relaxing.

That said, some games do relax me more than others. Project Gotham Racing 4, for example. I play on Easy, and there's nothing more relaxing that speeding around a beautiful track. However, I don't usually pop it in when I just want to turn my mind off. The only game I consistently play when I don't want to think about it is Minesweeper.

Lucid
It's a very relaxing puzzlegame.

http://store.steampowered.com/app/61100/

SuperBrothers: Swords and Sworcery EP http://store.steampowered.com/app/204060/?snr=1_7_15__13

Can't remember what I posted before, to lazy to try and find it so here's my updated list haha.

Morrowind/Oblivion: So relaxing because it's nice to just... walk. Not being shuffled down corridors to the next objective, just walking around, listing to the beautiful soundtrack.

Terraria: After the big 1.2 patch I've started playing Terraria again and loving it, it's nice to just build, to let your imagination go wild.

GunPoint: Another little indie, not sure if it's on GOG, but I love listening to the electronic/jazz soundtrack and trying to rig up something really complicated haha.

I found the Moreaff series of games to be quite relaxing, especially with a good MIDI synth.