Yes...Borderlands. When I first saw it, I hated it. The graphics looked terrible...like a cartoon. When I got it, I played the crap out of it for 4 straight weeks and nothing else. And I had 2 other brand new games getting dusty. My wife said
I was addicted to it. That was a 18-20 months ago and I still play it.
Crackdown 1. That 2 player co-op sandbox game came out of nowhere and was some of the most fun I ever had when it came out. I put hundreds and hundreds of hours into that game. In fact it was the first sandbox game on the 360 to offer a full 2 player
co-op campaign experience. Plus the ability to climb every building in the entire game through 3 full cities. Pure innovation that inspired GTA4 and Saints Row 2. Now SR2 is the best sandbox game I have played but Crackdown is still an excellent game.