There's a pretty awesome fortnightly Indie bundle thing over at http://www.indieroyale.com/. Basically it's a pay-what-you-want system where the base price fluctuates depending on what others pay. Pay the base amount - base price goes up. Pay more - base price goes down. It all goes towards the developers so it's not a Humble Indie Bundle charity event. Every game is Windows compatible and some are OSX and Linux compatible too. I've bought the both packs so far!