PSU for Beowulf?
If that doesn't work for you I'd trade it for any 360 game on your list except Forza 2, PGR3, Condemned, Halo 3, Crackdown, Mass Effect. (Already owned those plus I doubt you'd want to trade most of them for PSU anyway.) 99 Nights and Gun don't interest me as much though. (Already played Gun on the OG Xbox.)
(PM me if you want to set something up.)