Best burger in Denver? City Grill? (The place on Colfax by the Capitol building) And of course you've got Cherry Cricket!
In L.A., I'll give the best burger (fast food style) to The Habit. That place freaking rocks, and it make In and Out look like a pile of crap by comparison!
For Houston, hmm, I'll admit I love Whataburger for a quick fast-food burger, but that doesn't include the many very awesome "real restaurant" variations I've had out here!
Aaron (Glowrock)