So I plan on buying both Modern Warfare 3 and Halo Anniversary for my Xbox 360 tomorrow, and worst case scenario looks like that I'll be spending less than $120 for both games (even though I was fully prepared to do so, I had a whole plan out and everything). So now I turn to the gaming community to see where I can go from there. I now feel comfortable enough in my expenses to look for a cheap (<$30) third game to buy, but I don't really know what to choose.
My current game library is as follows: COD games (MW1, MW2, Black Ops), Halo Games (Halo 2, ODST, Reach), Borderlands, Just Cause 2, Need for Speed Hot Pursuit, Orange Box, Lego Batman, and Dante's Inferno. I'm also returning Brutal Legend and Red Dead Redemption due to me becoming bored from/not fully enjoying them and to get extra money off the purchases.
I'm looking for something that most people would find enjoyable but also time consuming (Fallout 3 and New Vegas are options, but I'm on the fence about them, mostly because I've never played a Fallout game before and therefore don't know how I'd enjoy them). Basically just looking for a good bang for my buck. I'm open to any and all options.