The official expansions for Oblivion were a lot of fun. Knights offers only one main quest with a few hours of play, but Shivering Isles packs in enough material to make it an RPG of its own. Definitely worth the price of admission for fans that can’t keep away from living out their virtual adventures in Cyrodiil. Check them out, or take some time to read what I’ve had to say:
Spend some time being virtuous in Knights of the Nine
Spend some time in an asylum in the Shivering Isles
After getting through those, I also tried out Earth Defense Force 2017 on the 360 which was a lot of fun. If Independence Day and Commando had a baby during the 50’s, it might be something like this.