I've played with real vehicles and it was fun. But, personally, if it isn't going to be used as troop transport, then the Polaris RZR is the way to go!
They're quick but not too big, come in 2 and 4 seater configurations as well as a small bed for cargo, and have convenient roll bars for mounting "Armour" or camo. Personally I'd love to boot around on scouting missions in the RZR!
http://www.rzrforums.net/gallery/dat...gazine_19_.JPG