Fallout: New Vegas. For the Xbox 360.
I got it on launch day and was... pretty disappointed with the finished product. The story was rushed and made no sense, the gameplay was frusterating, there were no fun dungeons, and there was just too much railroading.
A few years later I got a computer that actually worked, and picked it up on Steam for five dollars. The story is still awful, but all of the other issues can be fixed through modding, so, I don't regret that purchase.