I've merged you thread into a similar thread in the student life subforum. Please see the posts in this thread (up until you post).
But can you be a little specific? Obviously major cities are known for beng nightlife hotspots, so Glasgow, Newcastle, Leeds, Manchester, Sheffield, Bristol, London and others. Cost of living is obviously important for a student so those cities in the north are, generally speaking, best in terms of cost of living.
Cities with the most number of students will include Manchester (two universities in the City of Manchester, although they are both large, and more universities in Greater Manchester). Glasgow, like Manchester, has a very large student presence (with, as has already been said, the highest number of students outside London). Liverpool has three universities and one or two other Higher Education institutions. Newcastle, having the usual two universities, has a decent, but not massive, student population. However, as it is a compact city centre, and both universities are largely based in the city centre, there is a large student presence. Newcastle might also attract a number of students from Sunderland at the weekend, who travel by Metro, and does attract young people from across the country at weekends.
But then again, some peoples definition of "student city" is quite different and they will favour smaller, perhaps more homely, cities that are perhaps historic and with a strong student presence. Durham, York, Bath or Canterbury for example.