I agree with both of the above - pick primarily based on the course, but if it's a great course in an environment you can't stand, go with where you think you'll be happiest in the long run. As for the nightlife, I'm at York and there's really nothing to complain about, the clubs and bars are good and varied and Willow is an experience everyone needs to have (don't use the toilets there though). And yeah, Leeds is really close by train, so you can either go on your own time or with your college - I know my college organised at least one night out to Leeds this year.