The Counter has the best hamburgers in California, hands down. The only way they could improve would to have slightly better buns (like at the Peninsula Creamery) but otherwise their hamburgers are amazing! They have turkey, beef and veggie options, and you can even get a "hamburger in a bowl" where you get a hamburger/salad/toppings with no bun.
You choose everything going into your hamburger, including patty type, toppings (3 of the onion, lettuce, olive, etc. type are included), cheese (1 cheese is included) extra toppings (like bacon, etc.) and type of bun.
They also have interesting sides like sweet potato fries, crispy fried onions and shoestring fries that you can get separately or mixed.
They have a few other sandwiches, kids meals, and shakes/brownies/cookies as dessert. The service is a bit spotty but the hamburger makes it worth going to.