Hai Yen changed my mind (well, Denver should still feel lucky, but Chicago has put forth a strong contender).
Its lotus root salad was incredibly well balanced, which is very hard to do when something contains both mint and cilantro. Neither of these herbs overpowered the salad. Delicious strips of shrimp and tender meat were scattered through the salad and it was all accompanied by an especially tangy fish sauce.
The pho broth was the best I've had anywhere. I could have happily drunk it plain. But we ordered the special with everything, so it was garnished with about a million different cuts of beef (the only thing I couldn't find was tendon, but my dad said he ate it all by accident so I assume it was good). The beef was thinly sliced, not tough like it can easily get. The tripe was gathered in manageably small clumps so it didn't get stuck in your throat like it can easily do. Whoever arranged this bowl of pho was clearly thinking about the comfort of the eater rather than some purely aesthetic presentation of the bowl. It also came with a pre-arranged dipping bowl of sriracha and hoisin instead of having the bottles on the table, which was a little weird, but okay.
Our third dish was salt and pepper shell-on shrimp, which is the only reason this wasn't a five star place for me. The shrimp was not that fresh. Not bad-tasting by any means, but blandly not fresh, and that makes all the difference in a delicately spiced shrimp dish like this. It would have been perfect otherwise, with the frying somehow softening the shells but not overcooking the shrimp or being too heavy on the fry coat. My favorite part was eating the garlicky crunchy shrimp legs - yum!
Afterwards we refreshed with an avocado-jackfruit smoothie and a pineapple-mango-coconut smoothie. Out waiter was nice enough to give my dad's girlfriend a sample of the guanabana smoothie before she committed to ordering it, which was good because guanabana turned out to be soursop (I only know it by that name) and, well, soursop is one of the only things on Earth I don't like. Each smoothie comes with some cuts of random fresh fruit on top. Mine was watermelon, honeydew, canteloupe, and mango.
This was one of those meals where you feel fantastic after you're done, even if you're really really full. For me that's the sign of a perfectly balanced meal. I'd come back all the time if I lived here.