My suggestions : some pricy, some cheap...
Chez Panisse in Berkeley, California. It's a 30 minute BART ride from San Francisco, and it's famous as the origin of California cuisine. There's a small restaurant that books out very quickly, and a 'cafe' upstairs, which is more restaurant-like than cafe-like. Dinner at the cafe will set you back $US 100 for three courses including alcohol, and was great. I used OpenKitchen to book my table, rather than hang on the phone, as they only take bookings one month in advance.
Charlie Trotters in Chicago used to be one of 'the' places to eat in that city, and has since been eclipsed by a couple of other restaurants. It's still a great place to eat, with an 8-course dinner for $US 175 (price does not include state taxes and service), and adding matched wines to the dinner will bring the total price up to around $US 350 (including taxes and service). I thought it was a great meal, excellent service, and heaps of alcohol. It's a 'jackets for men' kind of place, and they have a selection of jackets if you happen to be travelling without one.
Momofuku Noodle Bar, East Village, Manhattan is one of David Chang's restaurants. We had a fixed price lunch mid-week for $US 25, which was very good, with the exception of the dessert, which was a peanut butter and jelly pie (I think this is an acquired taste). David Chang has a number of restaurants around New York, Momofuku Ko being the hardest to get into, with only 12 places.
Per Se in Columbus Circle, Manhattan, still appears in the San Pellegrino Top 50 restaurants in the world list (at #10 in 2011). It's also a 'jackets only' place, and the fixed price dinner plus booze plus service cost us around $US 450 per person a couple of years ago. It's pretty fussy, with elaborate food and excellent service, but I don't think it's particularly worth it. If you must try it, they have a couple of small tables at the bar where you can have some menu items, but not the degustation menu.
Asian food in Manhattan, other than Korean and Japanese, is not good compared with Melbourne or Sydney. There is a big cluster of Korean restaurants on 35th St, between 5th and 6th avenues.
Hill Country in the mid-20s, Manhattan, has been mentioned, and it's a great and fun place to eat. Pay-by-weight barbecue meats, with great sides. Price varies according to how much you eat...
Katz's deli is the place that featured the cough scene in 'When Harry Met Sally'. It's very much on the tourist trail, but I have to say, it was one of the best pastrami sandwiches I've ever had in my life. I still think about it.
New Orleans has a reputation for great food, but the local food is extremely rich, and to an Australian, pretty heavy and fatty. There's a cute wine bar just outside the French Quarter called WINO (Wine Institute of New Orleans) which is fun to drink in.
Washington DC is another town where calories, volume and speed appear to be among the most desired qualities in food.