B+
It's Pretty Sweet
The housing itself at Yale is phenomenal. It's almost all suite style, which means you and generally 3 to 5 other people (but there are suites as big as 12 people, and as small as 2) will have a few doubles and singles connected to a common room. If you have a larger suite (7 people or greater) you'll generally have your own bathroom inside of it. Overall the suites are pretty nice, and it's a great style of housing. Having a single is a good deal.
The only downside (as I view it, others love this) is the residential college system. Students are affiliated with a residential college for the duration of the 4 years they spend here. You will be living only with people who are in your college unless you elect to live off campus. Make a good group of friends in other colleges? That sucks. You can't live with them unless you all go through the hassle of changing your residential college affiliation (which will probably alienate the people you've been living with and bonding with during your freshman year).
However, rant aside, the housing is great.