I don't how GOG determines what games to add to their library, but I think it would be really cool if they could somehow port the xbox exclusive, Unreal Championship 2: The Liandri Conflict. It is one of my favorite games of all time and would be a great title to add to the website.

Unfortunately GOG is not in the business of porting games, they just make (more or less) old PC and Mac games run on contemporary OSes.
What was so great about Unreal Championship 2? I never played any of the console releases/ports of the Unreal series.

Unreal Championship 2 was pretty different from the regular UT games. It had a really fleshed out third-person melee combat system, and it sported a somewhat different, and more stylized aesthetic to the rest of the series. Go check out some gameplay videos on Youtube if you're curious.

There *was* a mod for UT2004 which was in development which ported most of the UC2 content over, but the mod team went silent a few years back unfortunately. Shame really. It's a game I'd also like to play on PC :)