If you want to party try the Irish bar in the Sheraton. It's the hotel at the end of the corniche that looks like a pyramid.
Souk Waqif is a good bet too.
Villagio is decent for shopping. There are a few American brand stores.
FYI Mega Mart at the Centre has the biggest selection of American foodstuffs here, but you'll pay through the nose for things like Funions & Doritos.
Except for the bases...Americans are few and far between.
Good Luck!