DIA has done a really good job with providing quality food options. In terminal C Root Down is the best IMO... awesome cocktails! Terminal B has Elways, and Terminal A is putting in a Mercantile... James Beard restaurant.
But that is probably the only good thing about DIA these days. I have been flying in and out of there for 16 years and it has never been more overcrowded than it is now. The construction doesn't help though and hopefully it is better when completed.