Here's the irony: I give it two stars b/c I just really hate going here, but I recommend you check it out at least once. The burgers are really high quality, the other food is fresh. But this place has such a d-bag feel to it, and it's always so crowded that it's both not fun and a little dirty.
The place is authentic and has a good story behind it. Leave yourself enough time to walk the grounds and the adjoining community garden.
And it's expensive (which means you pay too much for it, not that it's high value). I think I had a bacon cheeseburger, fries and a serve-yourself-at-our-outside-in-the-heat-fountain drink, it it set me back like $14.