Hangars are scarce up and down the Front Range.
There aren't any airports immediately to the west of Denver, due to the proximity of the mountains.
On the south side, there is KAPA, which is crazy busy. Friends of mine that used to be based there complained about the long waits to get departure clearances due to the heavy traffic in and out of corporate and DOD aircraft.
Northwest of Denver is Rocky Mountain Metro (KBJC), locally still often referred to as Jeffco. You've already encountered the hangar situation there.
North of KBJC is Boulder (KBDU). A vote is being held today about closing that airport. We'll hear soon how that vote goes. Needless to say, however, in that environment no new hangars are being built. The existing hangars, mostly owned by the city, are in various states of delapidation.
Northeast of Boulder is Erie (KEIK). I'm not sure of the status of hangars there, but I suspect the waits are as bad as at KBJC. North of Boulder is Longmont (KLMO), which is where I'm based. It is possible to build hangars at KLMO, as there is still developable land, but the recent new ones are very, very pricey. There are official waiting lists for hangars, which are many years long. Unofficially, I'm aware of people hearing about someone contemplating selling and getting lucky on a hangar. Part of the pressure on hangars at KLMO is that the Fort Collins-Loveland airport recently kicked approximately 50 GA airplanes out of city-owned hangars. Those folks have been flooding all the surrounding airports looking for space.
Swinging around to the East, there are a couple residential airparks. There's also Platte Valley (18V), which is a favorite of mine for a quick hop, but it's pretty far out in the boonies. There's KDEN of course, but regular folks avoid it as fees are high and controllers aren't interested in GA traffic smaller than corporate jets. Just south of KDEN is the Colorado Air and Space Port (KFCO), formerly called Front Range Airport. It has private hangars and may have space to build additional ones. I don't have any recent info about wait lists there. It probably is worth checking.
Long answer, I know. But that's an overview.
Best of luck, Ken