Below are games that I completed in less then a week, and should be easily done in a few hours or less by anyone with some skill.

Defcon
Time Commando
Book of Unwritten Tales + Critter Chronicles (really short)
Tomb Raider 2 + 3
Deus Ex Invisible War
Stacking
Tales of Satinav
Primordia
The Last Express
Sherlock Holmes and the Silver Earring
Journey to the Centre of the Earth
Resident Evil 1 + 2 + 3 + 4
Army of Two + 2
Unreal 2
Blake Stone + Planet Strike
Costume Quest
Worms + 2 + Armageddon
Capsized
Larry (all games)
Broken Sword + 2
Blackwell Bundle
The Cat Lady
FTL
Hotline Miami
Resonance
Simon the Sorcerer + 2
XIII
Alan Wake's American Nightmare
Snapshot
Splice
GTA + 2 (you might finish 3 in a day or two at a push)
Freedom Fall
The Dig
Full Throttle
Monkey Island +2 +3


All TaleTail Games