@kinggen - okay, Campus West: here goes!
Firstly, here's the campus map so you can see what I'm referring to.
Regarding the actual size of the flats in each college, I'm not too sure I'm afraid. Your best bet is to explore the accommodation pages which will tell you what's available in each college. There are 360 views which you'll find helpful.
So, I'll start at Heslington Hall (administration buildings and not usually accessed by students) and I'll move round the lake clockwise. First up:
Halifax College: Built in the 1980s / 1990s, its set back from the main campus fairly near the sports facs on campus west. Overlooking fields, it has its own shop and common rooms. There is a shuttle bus between accommodation and the rest of campus.
James College: Some of the buildings date back to the 1960s (the original Goodricke college), but other parts were built in the 1990s. It has a large restaurant, the Roger Kirk Centre, and a coffee bar. It's opposite the campus west Sports Centre and is close to the students union buildings. Nearby are the depts of Maths, Physics and Electronic Engineering and over the bridge to Environment and Biology.
Wentworth College: largely for postgrad students with great views over the lake. Has a cafe which anyone can use.
Carrying on round the lake, there are the depts of Environment and Biology.
Then you get to ...
Vanbrugh College: Dates back to the 1960s with newer accommodation built in the mid-2000s. Has a food court and a bar. Close to the Information Centre, with various student support services, and Market Square with a mini market and other shops/services. Close to History, History of art, Language and Linguistics, Music, Philosophy. University Road close by with buses into town. On the other side of the road is the main library. Outside Vanbrugh is 'Gregs Place': a very nice spot to sit and take in the lake view.
Carrying on round and past Central hall (looks like a spaceship!) brand new teaching buildings, and on to....
Derwent College: Again, has a cafe. It also has two bars run by the students' union. This is the oldest college on Campus and has lovely views over to Heslington Hall and its gardens. Close to the departments of English, Politics, SPS, PPE and Education. Derwent has taken over the original Langwith College buildings, which moved over to Campus East 9/10 years ago. Close to one of the University bus stops outside Heslington Hall.
Across the road from Derwent is the Science Park. The Management School has just moved here from Campus East, and is sharing its premises with Social Policy and Social Work.
So we're back on University Road and we cross the road to ...
Alcuin College: Some of the buildings date back to the 1960s, and others were built in the 90s (I think??). situated behind the main library and close to the departments of Chemistry, Health Economics and Hull York Med School. It has a couple of cafes close by, plus the one in the library. Nice views as its quite high up. Much of the accommodation is set around grassy courtyards.
The main thing to remember is that you can walk at a (fairly) leisurely pace around the lake and complete a full circuit in 15 - 20 minutes - even shorter, when you cross the bridges. I wouldn't say you need to live in a college close to your chosen department ... unless you really wanted to! All the colleges have got places to eat / drink, and a couple of the departments have got small cafes too (eg Management, Biology).
I think I've got everything: apologies to any of the smaller schools / study centres that I may have inadvertantly forgotten!