There seems to be some confusion about what OP meant by “residential colleges”. The classic system at Yale and Rice, which seems to be picking up steam at other colleges (I think they like it as an alternative to Greek life) works like this: ALL freshmen are randomly assigned to one of the school’s residential colleges, and they remain affiliated with that “college” for their entire four years. It is not the same as the theme housing offered at other schools where some of the students participate and others do not.

U of Chicago
Franklin and Marshall

DD was put in EcoHouse at UConn. They always win the competition to conserve. As a parent I thought, "ugh, now I have to worry she won't shower or turn on the lights" Of course it all worked out. She made great friends even though she didn't ask for that housing. Many themed housing on many campuses. And I think all state flagships have residential collegese, at least a few in addition to honors.

Is this what most LACs call “living/learning communities?”

Princeton

The ones at Yale are randomly assigned freshman year. Harvard you apply for sophomore year, which means that some houses get reputations. It depends how the program is run.

This isn't quite like the full freight residential college system that you are describing, but UVA has three: Brown College at Monroe Hill, Hereford College, and the International Residential College. I've heard that they're all wonderful places.

Also, before the UVA bashers roll up, I am not affiliated with the school! I have just been going on toooons of college tours with DC recently, and this popped into my head.

Residential colleges are NOT theme colleges.

Most colleges have this. I’m not sure how I feel about them as some tend to serve as an avenue for segregation like the “Africana house” and the “Asian studies house” at Cornell.

UMD has them.

My son is a senior at Rice and has loved it there. His residential college has been a great base for him socially, but he's also made friends in classes and in activities he's participated in outside of his residential college. To clairfy, the residential colleges are not themed housing -- all first-year students are placed in residential colleges regardless of major or other interests. So, every residential college has a mix of students from different years, different majors, etc.

Lots of colleges have theme housing. WM offers honors housing to the Monroe scholars with seminars. Substance free house, minority student house and language immersive housing is common. We were looking at the Oberlin housing, and there is science fiction fan theme housing. Some schools also have co-ops, where kids take turns making the dorm meals.

I believe Yale has residential colleges.

My child’s friend is there now and hates the concept. Very clicky. Some areas think they are better than others. If you change majors, it gets complicated. The kids don’t find friends based on personal likes, just their intended major.

We toured Rice and it's now tops on DC's list especially because of the residential college system - kids seemed super dedicated to their living learning community and she loves how inclusive it seems and how it kind of is like Greek life without the downsides of Greek life. I also had this great experience at Notre Dame...where there was so much going on in your dorm, most people lived there all four years, there were things like dorm competitions and dorm formal, etc.

What other schools?