The US is overrun with national chain restaurants. There are lots of sit-down places like Olive Garden, Applebee's, Outback, etc. that you can find in most any sizeable city, but I'm sure you'd rather have a good local restaurant when you're traveling, not 50 McDonald's that serve the same thing. Bar & grills here can be really hit or miss, in my experience.
It seems a lot of people like to use Tripadvisor (http://www.tripadvisor.com/) to scope out places when they travel. I've only glanced at it a few times, so I don't know if people get into portion sizes and the like with restaurants (it's probably more along the lines of "this was good food at a reasonable price," but that might be one way to find good local restaurants. Yelp (http://www.yelp.com/) seems pretty popular these days (and you're more likely to get local people rating), but it covers way more than restaurants. Also, it doesn't cover everywhere in the US, but it does hit a lot of popular places with tourists. There's also UrbanSpoon (http://www.urbanspoon.com), although I'm not sure if that is as well known as the other ones I mentioned, but the coverage looks to be better than Yelp as far as the number of locations go.
Re: Well, this turned out to be really long.... :-D
It seems a lot of people like to use Tripadvisor (http://www.tripadvisor.com/) to scope out places when they travel. I've only glanced at it a few times, so I don't know if people get into portion sizes and the like with restaurants (it's probably more along the lines of "this was good food at a reasonable price," but that might be one way to find good local restaurants. Yelp (http://www.yelp.com/) seems pretty popular these days (and you're more likely to get local people rating), but it covers way more than restaurants. Also, it doesn't cover everywhere in the US, but it does hit a lot of popular places with tourists. There's also UrbanSpoon (http://www.urbanspoon.com), although I'm not sure if that is as well known as the other ones I mentioned, but the coverage looks to be better than Yelp as far as the number of locations go.