Movies:
The Groomsmen
Corrupted Minds
Dead Mary (HD)
Flags of our Fathers in HD

TV
The Animatrix - First Episode free this week.
There is additional Animatrix content that will be free with specially marked Matrix HD DVDs

Friends S4 & 5
Gamehead S4
Tornado Intercept
Tsunami: Killer Wave
Violent Earth
Volcano: Nature's Inferno
World's Most Dangerous Gang
Basketball Diplomacy from Mao to Yao
Cameramen Who Dared
Eternal Enemies: Lions & Hyenas
FBI, The
Is It Real (6 eps)
MegaStructures: Mega Plane
Pearl Harbor: Legacy of Attack
Search for Kennedy's PT-109
The War Next Door
Through the Lens
Asteroids: Deadly Impact
Avalanche
Land of the Anaconda
Lost Subs: Disaster at Sea
National Geographic's Most Amazing Moments
National Geographic's Most Thrilling Moments
SuperCroc
Tiger Shark: Predator Revealed


Edit: Clarified Animatrix being free

Edit: Added even more clarification around The Animatrix

Per Major Nelson