Best XBOX indie games?

What in D Hell is an "Indie" game?

I imagine it means different things to different people, but for the purposes of this thread I meant those games that are featured on Xbox 360 as XBLIG, or Xbox Live Indie Games.

Most of the games there are made by small firms or individuals using XNA and are sold for 80 MS points (or $1). Some are sold for a little bit more or up to 400 MS points, but 90% are 80 points. They certainly aren't AAA quality titles, but some of them have really unique gameplay. Gateways was certainly one of those, featuring "portals" in a platformer. With 2,500+ titles on XBLIG, there are certainly some gems in there (often well hidden!).

I don't have a Playstation, but what kind of "indies" do they feature? Are they all free?