Indie games are pretty much the one thing you won't find for free, unfortunately. Otherwise, about the only thing you can do is hope for some sort of special, or stick to game aggregation sites like ArmorGames/Kongregate/etc.
If you're not beyond pirating stuff, you can always download an emulator (GBA/NDS, not sure how good the newer console emulators are, though) and pirate some games. Was basically how I killed the time when I didn't have internet for 3 days.
Damn you Golden Sun and your points of no return