It sounds like you are not necessarily thinking of 55+ housing -- just something away from the high energy student areas. (BTW: I don't think I would refer to student housing as 'ghettos').
You might want to watch for listings at the Peleton on Arapahoe. Some students do live here among a mix of ages. And there are some nice amenities like pool and exercise room.
Vistoso is also a very nice venue. It is located near a shopping center with grocery and other basic shops. There is a smaller weight room and a nice courtyard where events are held. It also is not far from the East Boulder Rec Center. There is indoor parking and the entire building is no smoking.
Thanks for your question about Boulder. In terms of what you are looking for, think of Boulder as a target with the bullseye being the University. The closer you are to the bullseye, the more students (specifically undergraduates) you'll find. As you go further out there are more owners and less renters. There are some exceptions close to Pearl St., but the price point is much higher, which is why there are fewer or no renters in those buildings. They have more amenities and a higher price point (starting around $500K). An example would be this property:
The Steelyards are new and trendy (as is the community there) but it depends on whether that is your taste or not.
Of course what you are looking for would play into this.... i.e., do you want to walk to a grocery store, restaurants, coffeehouses, etc or would you rather have more open space around you? What type of activities will you be doing (trail walking, running, etc)?
Some complexes' HOAs keep track of their owner occupancy rate and most have a very good idea. This is something I can do for you once you have specific buildings you are interested in.
Please let me know if I can be of further assistance or if you have other questions.
North Boulder also has some nice areas that are quiet. To completely answer your questions you should consider:
1) Your price point? (expect to pay at least $300k but up to $1.5 for housing in a non student area)
2) Do you want to live within walking distance to pearl street?
3) Do you want new construction?
4) How big of a condo do you want?
5) Do you want elevator access? Few of the older buildings have elevator access
Let me know some more details on your desires and I can further assist you with your question. There are almost 500 condos for sale in Boulder right now so there is a lot to choose from. Dakota Ridge and Holiday are nice and there are also some condos in the Gunbarrel area that I like a lot too. The further north you go the more expensive you get and the less renters you will have.
I have a search on http://www.boulder-co-homes-for-sale.com that may help you.
Web Reference: http://www.definitelydave.com
The University town feeling is evident in Ft. Collins if you are open to different areas. Broomfield is nice for it's conveniences, layout and proximity to everything else. If nothing else it would be a good consideration for you guys.
The Strange Team
Keller Williams Preferred