mary's - going mixed this october (yay!), have a v complicated room ballot but ensures that you only have to share a room one term and do not got stuck with a really bad room. mary's have the following blocks - ferguson (main block wehre you eat all your meals and the oldest part), mews (behind the kitchens - worst block cos rooms are so tiny but a lot of the university of japan students seem to be in there this term), williamson (new building - where most freshers are), then teikyo residences (some mary's girls are in there, not many tho, is mostly university of japan students on exchanges and some random cuth's boys cos cuth's wud house you down in london if they could - if this year is anything to go by!).
most first years are down in the williamson block and these are all singles so creates a nice community just down the steps from the older ferguson building. if u find yourself in ferguson is most likely that you'll be sharing but there are some pretty nifty doubles in the roof with gabled windows and sloping ceilings. there is no doubt that some of the rooms need refurbishing and some of the bathrooms too but on the whole the college is of a generally good standard and if your floor bathroom is in a bit of a delapidated state can always go use another floor that has much nicer bathrooms - seems to be common practice. all rooms have a washbasin and there are a few ensuites. all ensuites are single, except two, and these go out to 2nd and 3rd yrs however the two double rooms with ensuites do go to first years and if you play the system, like i did, it is possible to get an ensuite for at least one term.
if you have any reservations about sharing it's really not that bad - i shared for my second term and it worked out fine, it really is a lot easier and more fun than it sounds (this coming from someone who's never shared a room in her life!) although i was friends with the girl for a term first. sharing in your first-term tho, based on others' experiences is pretty darn convenient as it means you'll always have someone to go down to dinner with and you'll always have someone to talk to if u feel a bit lonely - the college does quite a good job of pairing people together with similar interests.
we also have 3 tv rooms/jcr's - one of which will have a plasma screen by next october and all are getting sky so should be fun, fun, fun!
it really is best to come and look round the colleges tho to get an idea of the place as each has it's own unique character- highly recommended.