Like the title! I normally am very critical of Expansions, but sometimes they build upon the base game in very unique ways. I love Dead Money for Fallout: New Vegas, it has the sharpest character writing and turns the game into a Survival Horror experience while remaining authentically "Fallout."
What are y'all's thoughts?
BioShock 2: Minerva's Den
Half-Life 2: Episode Two
Halo 3 ODST
uh, the Zoo Tycoon expansion that let you have dinosaurs