Not sure if this is in the right place, but I'll help out anyway.
If you only have cats, I'd suggest the AC All Cat Clinic off Broadway. They don't charge ridiculous prices that most of the vets around here do, and their services are just the same! Maybe even a little MORE personal, who knows, but I didn't notice a difference between one that charged crazily and this one, so.. I'd definately recommend them!
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.
I don't know anything about Denver, but I'd watch out for "cheap" vets. I was shocked at how much everything costs at the vet's office, but I tend to just put everything on a credit card and worry later how to pay for it. Care Credit is a good option, I understand, if you run into problems. Good luck!
Where abouts are you in the Denver area, and how far are you willing to go for a good vet?
I highly recommend my vet, but we're over in Lakewood on the far west side of town. Their office is between Kipling and C-470 on Morrison Road. Here's the directions page on their website, where you can also find contact info: