I played the first few hours of Too Human alone and thought it was boring, but I've always thought it might be fun w/ a friend. It's like 1.49 at Gamestop. --- Halo 1 LAN vid: http://www.youtube.com/watch?v=VhjWnJU2EKY
This game called God Mode is really under the radar, but I do not believe it is local. It starts off kind of difficult until you get a feel of it and learn to beat the levels with oats. Then you can level up weapons. For 10 dollars, it's not bad.
Renegade Ops is an overhead XBLA game that I think should be 10 dollars by now. I really enjoyed it and am surprised it did not sell as well as I hoped. Great overhead twin stick shooter in vehicles. The graphics are really good and so are the physics and explosions.
Outland can be a really great co-op game if you have a friend. It can be really difficult and you may actually die a few times or more. --- I served 8, in war... my father served 23, in war... both of my grandfathers served, in war. WWII, Korea, Vietnam, Desert Storm, GWoT, etc. - ScarecrowES
I imagine gears of war is down at that range, Rainbow six Vegas maybe Hunted: the demons forge.
If not check out some arcade titles
yeah I just got the Gears of War Collector's edition for $11 after shipping...so yeah that is getting good & cheap.
It's 20$, but it's still good...try out Spec Ops: The Line...I have heard some good about it on Coop. --- http://youtu.be/HR8Ia6vyV5Q She's an endless war, she's a hero for the lost cause,Like a hurricane in the heart of the devastation