Little Big Burger - In the Pearl District (near Powell's) in Portland, OR
There are a few of these places around, but I've only been to the one in the Pearl District. Of all the food places that use the business model of a limited menu (like In-N-Out and Five Guys), Little Big Burger is climbing to the top of my favorites list. I like Five Guys, but it's SO MUCH FOOD... When I go to LBB, I always want to get two burgers when I see other people eating that little burger, but I don't, and I haven't ever regretted it. It's the perfect amount of food, and it's quality food. I recommend this place when you just want something simple and you want to be full but not sick-full (which I never want and always regret when I get to that point). Their Chevre and Bleu are both good. FYI, they cook every burger to Medium which seems more like Medium-Rare to me, unless you tell them otherwise.
Little Big Burger Website