Other than this thread, I'm not sure. It's probably best looking on the York Unis page. I go to Derwent, so I'm bound to be a bit biased, but I'll give it a go:
Alcuin: Nice accomodation, but on the more expensive side. It's near the library and fairly central. Their blocks are organised in quads, with a grassy area making up the quad area. I really like the Alcuin people I know, they're all really friendly but they say the college events are pretty dire. The blocks are made up of flats and I've heard that some people are a little unsociable and tend to isolate themselves a bit, so if you're in a flat full of them it might not be so fun - what are chances of that though?
Derwent: Not-so-good accomodation. It's not got boarded up windows and spiders crawling everywhere, but it's not nearly as swish as somewhere like Alcuin - but it is cheaper, and i've heard no complaints over last year about it. It's situated fairly centrally, near to Heslington Village and is organised into 6 blocks, each with 3/4 floors, and, unlike other colleges, it doesn't have a keycard system incorporated into the doors - this means that, as long as you know the code to one block, you can roam freely on all floors, which adds to its sociability. There is a nice big green area called The Quiet Place situated outside B block with a bbq pit, which is great in the summer. Derwent events are by far the most active of all colleges. Unlike other colleges we regularly sell out on our events - our main one being the themed Club D events, which run 3 or 4 times per term. We organise and hold the largest annual event on campus - Big D, where we transform Derwent and Langwith into whichever theme the committee chooses - this year it was SinneD. So yea, Derwent has quite a good reputation for being the most sociable college with a great college spirit, all the blocks are pretty integrated and everyone knows everyone. You might say I'm bound to say that 'cos it's my college.. but I'm confident most non-Derwenters would say the same. A negative for some would be its switch to becoming catered as of next year (there may be some non-catered though, I'm not sure).
Goodricke: Goodricke has, as of last year, been relocated to York's new campus - Heslington East, about 15 minutes walk from main campus (I walked back from there highly intoxicated one night so this is a very rough estimate), though I believe there is a regular (free?) bus service to the main campus. It's a massive ongoing development which involves moving not only Goodricke but other colleges as well as several departments over to the new campus. Due to this, the accomodation is very new, though has had a few teething problems in Winter and is probably a bit more pricey, so you're likely to get a few more rich kids down that end. I've heard their events are actually really good, and they have an xbox in their jcr attached to a projector, which is pretty snazzy. I don't actually know too many people in Goodricke so I'm not massively sure what it's like there, from what I've heard it's quite cliquey though.
Halifax: The largest college, situated about 5-10 minutes walk from central campus. It's right next to 22 Acres (the sports fields), and therefore not far from the gym and tennis courts, so it's a good college for sport enthusiasts. It's organised in houses of 10 (?) within courts, which again are kind of like the quads in Alcuin. Halifax is actually the only college that I don't know someone from, so I can't comment on the quality of their events. They also have a costcutter in their college with basics, so you don't have to trek all the way on to the campus costcutter.
James: James is also situated right in the middle of the sports area of the campus. It's perfect if you're going to be going to the gym or doing any kind of sport at York - and consequently they tend to have pretty decent sports teams. It's accomodation is pretty swish too, though they may've taken over some of Goodricke's old accomodation on the Hes West campus - which would be pretty grubby in comparison. Their accomodation is also situated in blocks, organised again in quads, with biggish grassy areas. I know alot of really nice people in James, and if it has the same quality of people next year I'd highly recommend it. I think it's similar in many ways to Alcuin to be honest, it has the same pros and cons, except James is situated in a better location for sports. Plus, I've not really heard that much about unsociable people in James.
Langwith: Due to its "rivalry" with Derwent, I'm bound to dislike Langwith. But it does have some pros. It's very central, it houses the Student Union Bar, the Courtyard, and contrary to popular belief, does have some quite nice people. However, though it houses the Union Bar and is rather nice, all other colleges also have their own college bars, they're just not as nice - however, it's shape makes it terrible for events. We did Derwent Invades Langwith to the Courtyard when our bar was (and still is) being refurbished, and it wasn't nearly as good. I have heard their events are pretty terrible and personally I'd advise against living there. Its accomodation is as nice as Derwents (they were built around the same time, with the same ugly design) and is also organised in a similar manner to Derwent, with floors within blocks - the only difference being a keycard system is in use, restricting access. The majority of Langwith is also becoming catered from next year, and I believe you'll have to make the trek over to Vanbrugh Dining Hall every morning for your breakfast (and dinner). It also doesn't have a great deal of green space to itself. So yea, in my opinion avoid.
Vanbrugh: The most central college. It's no more than a few minutes walk to the sports centre, the library, most large lecture theatres and also houses the campus Costcutter. It has new and old accomodation. The new I'm guessing will be very nice, on par with Alcuin and Goodricke, with large kitchens. The old accom is similar, and I'd say if anything slightly worse, than Derwent and Langwith. It's quite good for music and the arts generally, though their events do seem a bit dire. From those I've met they're generally very nice and sociable. Again, it lacks nice big green areas (can you tell I like green areas?). Also Fairfax House, an asylum-like mansion about 10 minutes from central campus, is part of Vanbrugh. It's on the way to town so useful for nights out I guess but it's no doubt at least a bit of a pain having to walk further than you would otherwise have to for seminars and lectures. I've heard it's quite fun though and they've had the odd party which sounded cool.
That's all I got I'm afraid!! Hope it helps!