Southwestern - Jack N Grill (25th & Federal) - New Mexican Style, fantastic burritos and green chile, surprisingly good burgers.
Steak/Meat - The Fort (Morrison, CO) - Not the best 'steakhouse'. But seems to be a sort of iconic Denver place. Alternately, the Buckhorn Exchange (10th and Osage), where I tend to think the food is a bit better.

I'm not sure what else I can think of that would be a 'Denver' meal, though there are plenty of other fantastic restaurants in the city. Fruition does farm-to-table pretty well, I love Mizuna, Domo does the best Japanese food in town (ignore anyone who thinks Sushi Den is better... sort of kidding :P)...