The weekends are for escaping reality. Why worry about taxes or homework or that leaky pipe in the kitchen that's causing mold to grow across the floor when you can run away to be a postal delivery person, Indiana Jones, or a bumbling kid in a crazy person's basement?
Donkey-Me: Raiders of the Lost Ark (Mac/Win/Linux, free) - Donkey Kong meets Indiana Jones. Whodathunkit? A description as simple as that sums up the game quite well, but it doesn't begin to explain the lengths developer Bruno R. Marcos went to make the game true to its source materials. Leap over snakes, skeletons and natives instead of barrels, pick up a whip instead of a hammer to fight your way upwards. The music, the controls, the setting, the artwork... everything is perfect for a truly captivating bit of nostalgia.
Monsters in the Basement (Windows, free) - Originally made for a Ludum Dare mini, Monsters in the Basement is a slow-paced Pac-Man-like horror game. Exploring an abandoned house, you and your friends inadvertently discover an abandoned basement. So, you go inside. Using your flashlight to see the paths ahead, collect the batteries to move to a deeper floor. Keep away from the monsters, of course, and use flares and guns when applicable to stay alive. Surprisingly intense, especially with all those shadows filling the corridors.
Fakteur (Windows, free) - Delivering the mail is the best job in the world. Set in a world of paper, Fakteur puts you on a bicycle and gives you the ability to read, alter and deliver mail to the wonderful people of the land. Want to make them happy? In the mood to devastate each and every one of them? It's up to you! The English translation is a little hit and miss at times, and there isn't too much interaction or "game" in the game, but its alluring visual presentation and environments are nice to ride through and experience at least once.