Which London uni is best for the social life?

Depends what you're into. If you like dubstep or (for want of a better word) ethnic music then Brunel is the best place. I didn't know what dubstep was before I started but now it's been piped through my window for a year I'm familiar.

I'm not really that into live bands etc. I prefer spending the evening in a bar with a couple of friends, or going shopping in covent garden.