My favorite surround games to show off are
*Skyrim
*Fallout: New Vegas
Wings of Prey
Batman: Arkham City
Red Orchestra 2
GRID
Dirt 3
Portal 2
Metro 2033
Black Prophecy
*Skyrim and New Vegas can have quite the fisheye effect in surround but it increases the immersion so much I simply would do without it and aside from sims i think they are the best showcase for surround. You can really minimize the intrusion with texture packs. I use NMC Texture Pack for New Vegas. I have a number of texture packs for Skyrim but the most useful texture replacements are for trees and mountains since they make up most of the scenery and are usually what gets zoomed in on with the fisheye effect.
These are the best mountain textures for Skyrim in my opinion.
@Bifurk8 - Can you post some images of FS2 in surround?