Best. French Fries. Ever.
Also they have great onion rings, fried zucchini, hot dogs... I don't eat burgers really, so I can't speak to those. I am obsessed with their tuna salad, though.
I never thought I'd be ordering tuna salad sandwiches regularly from anywhere. Tuna salad has a tendency to be that unpleasant gray or pinkish color, and have a tinge of fishiness to it, if its not fresh enough. That is never the case at Chicago Hamburger Co. This might sound strange, but their tuna salad is the most pleasant pale green color I have ever seen. It's because they put relish in it. Lots of delicious relish. I am in love with their sandwiches, and although I used to devoutly order Polish sausages & fries, I can't turn my back on my new love. Not the first thing people think of ordering when they come here, but it's definitely worth a try.