Tae Fu in Villa Park for Amerinese, but you'll also need to get the Mongolian Beef, and even then may still raise an eyebrow at the rec (it may be a "me" thing. Edit: zoid, jinx).
Lao Sze Chuan in Downers Grove should have the standard version, with better wok hay and delicious caramelized carcinogens than most. After a conversation about the dish in Chinatown, Tony sent us us a "Shangdong style" version that had spicy pickles and lots of lily buds in it (this was about 6 years ago), and perhaps more funky / fatty pork than the usual sliced lean pork chop; if you ask DG for "Chinese style" they may be able to do something special for you. Hoisin makes a big difference in the dish as well - Lao Beijing has my favorite, which they must doctor (or perhaps it is just elevated by the northern pancakes with smoked pork).
I'd be curious to know if anyone makes mu shu with house-made pancakes. When I've ordered large quantities for takeout from Lao Sze Chuan and Lao Beijing, they've actually included the flatbao in-package, straight from the fridge. They're fine. Azteca flour tortillas are the dealbreaker, and sadly prevalent.