Alpha Protocol -
Would love to see a sequel, the first game wasn't very polished and the gameplay wasn't the greatest, but it was good fun and had some excellent twist and turns in the plotline, and for a standalone game it has excellent choice impact.
Kung Fu Chaos -
To this day is still great fun on the Original Xbox, very humorous and clever with some really fun levels and minigames.
Simpsons hit and Run-
Loved this game so much, for any simpsons fan it was a delight, so many references to the show and not only that but it was a really fun game too.
I would like to see Obsidian make another Fallout too.