Origin Key from the Humble Origin Bundle for Red Alert 3 Uprising. Not 100% sure if this key is the base game and the standalone expansion, or just the standalone expansion.
Desura Key (From Groupees, I think) for Battlepaths (which gets you a Steam Key through the Desura client). Pretty sure I still have this one floating around.
Indie Gala Key links for:
RUSH.
Afterfall Insanity - Extended Edition
Mata Hari
Steam Keys for:
Deponia
Skyward Collapse - Complete
Edit:
Added a couple Steam Keys to the list from Bundle Stars.
Edited, Jul 19th 2014 8:08am by TirithRR