Short: It's In and Out, and it's a good one. Haven't been to a bad one, but this one is good.
Long: It's VERY busy, but the service is decently fast for how busy they are. Food is on par with every other In and Out I've been to; no complains.
I recommend just a plain Hamburger as you get to taste the meat and veggies, and Animal fries since the regular ones are kind of bleh~