There are so many chain restaurants in the United States it may be impossible to try all of them! I usually stick to small unique restaurants but if friends or family want to go to a chain I'd choose between:
-Carraba's
-The Melting Pot
-PF Chang's
- Jimmy Buffett's Margarittaville

PF Changs is not the best chinese food I've ever had but it hits the spot in the USA since it is hard to find chinese food that is not take-out only.

A couple I haven't seen listed amazingly enough:

Pei Wei is a more casual PF Changs. Great take out on the road.
Smokey Bones - I haven't tried the other BBQ places listed, but smokey bones has good ribs and great baked beans.

Fast food = In-N-Out Burger or Sonic (Hey...at least they're made fresh :p )

Everyday = Outback Steakhouse

A little nicer = J.Alexanders

Very Nice = Morton's

Lettuce Entertain You
 

Lettuce Restaurants have incredible quality controls...Wildfire is the closest to a "chain" at this point and the food is superb. TRU is one of the best in Chicago period. Some independent restaurants are crap. You just have to jusde for yourself.

Wirelessly posted (BlackBerry7520/4.0.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 UP.Browser/5.0.3.3 UP.Link/5.1.2.16)

A more regional choice is Red, Hot and Blue. I've eaten there in Chicago and Dallas.

Nope
 

Nope- they're aren't any. If the world has any hope of retaining any cultural or geographic individuality, you must avoid all chain restuarants (and stores, and letters, and gangs) at all costs.

hurlimann

And sit in your home and never go out to eat and never shop to buy something to prepare to eat. :D Actually, I think there are already places in the U.S. where that would be the case unless you drove long distances - and bought, of course, gasoline from an independent dealer.

Well then the obvious answer is to stay the heck out of the US. :D

I loved eating at The Keg when in Toronto - fantastic baked spuds

I think Houston’s is exceptional for the price. A little on the high side, but fairly reasonable by New York standards, especially as sides are included.. Friendly service and maybe the best pork chops I have ever had. The desserts are not as outstanding (Cheesecake Factory would get my vote here), but definitely okay.

Macaroni Grill, Cheesecake Factory, Smith & Wollensky, Ruth's Chris

This isn't an enormous chain like The Olive Garden but they are in large cities, especially near water and by vacation destinations.

Phillip's Crabhouse

I just went to one in Baltimore, MD and they had a buffett for $25.00 a person. I do not usually go to buffetts but this consisted of crab legs, crabcakes, oysters, clams, mussels, shrimp, clam chowder, deviled crabs, clam strips, softshell crabs, hush puppies, and more and a full dessert bar.. it was amazing and so cheap for endless amazing seafood!

Chipotle (McDonald's) and Baja Fresh (Wendy's).
Yummy.

If you include local/small regional chains, then I would have to say Box Lunch in the MA area and Pizzicato Pizza in the PDX area. Pho Hua is another good one, as they have excellent, very cheap Pho, but they're based mostly in Asia. They do have several US locations, particularly in places with large Vietnamese populations. I'm sure someone else has listed this, but In 'N Out Burger.

Yes Chipotle is a fav, Baja Fresh was ruined for me when it was the only place near my office open on summer weekends- something about eating from there when stuck in the office 14 hrs/7 days a week ruined it for me.