Games of Joy - Your Recommendations?

[Pifanjr]

Although it's not quite as easy to just pick up and play as some of the other recommendations, the loading screen of Black and White is quite right when it says "Throwing villagers around is great fun!"

As a bonus, it's available for free as abandonware.

 

[Zloth]

"Stanley Parable" comes up too as a game that doesn't require brainpower and certainly lights up the mood.

Be sure to play the demo, too. It's essentially a second game all its own! (Also, you'll get to hear the word "eight" pronounced better than you ever have before.)

 

[Rolfil]

Have a look at some of the relaxing games mentioned on the forums.
Raft doesn't require a lot apart from fighting off a Shark, although there is a Peaceful mode where it won't attack you.