Asian Fusion Bistro has an awesome menu with the right amount of variety. I've yet to have a meal that wasn't fantastic!
The staff is friendly and helpful and they're always good about making adjustments or substitutions.
Atmosphere is tasteful but no frills, and it's not too loud.
There are good Thai restaurants in downtown Milwaukee, sure, but this place ranks right up there [with their Thai dishes]. And their naan is some of the best I've tasted, in Wisconsin or otherwise.
Finally, I'll leave you with two words: mint chutney. :)