I can't help with Denver vets, but talk to your neighbours, colleagues, anyone you talk to in your area who has pets and see who they recommend.
I also recommend having a vet fund that you put money aside for, so you have the money there for planned and unplanned visits. Vets are unfortunately expensive! For things like vaccinations, there's often low cost vaccination clinics at shelters and pet stores, and that will save you a whole lot of money - but you will get just the vaccination, and not a full check up. I take my girls to the vet for a yearly check up ($50/checkup), then to the shelter for their shots when they need them - about $10/shot, which is a lot cheaper than the vet.