Best Burger. Period..
I used to be a big In 'N out fan until a friend told me to try Fatburger. Both chains are from California, but that is where the similarities end.
Fatburgers are made to order, which is great, but there is something about the taste of the burger that gets me everytime. I can tell they use high quality ingrediants--the cheese for instance tastes like real cheese and the lettuce and tomatoes are always fresh. My wife always gets the turkeyburger. I have to admit--I like it too.
The onion rings are killer. Probably the best I have ever had. Ever.
If you go, make sure you get one of the milkshakes. They are the icing on the cake- The bun on the burger.