Nottingham is definitely the best one to go to, of the unis you've applied to, in terms of employability.
Obviously, I wouldn't limit your choice just to that. However, I'm at UCL which allegelly has great library facilities and I'm really starting to get ticked off with the number of books not available!
Compared to Bristol and Nottingham, Warwick seems slightly off the radar for Law. For Economics/English I know Warwick is comparably better.
Go to the open day. I wasn't too impressed by the Warwick open day. Bristol is as you'd expect- and if you're still pining for the whole Oxbridge set-up, I'd say go there and apply to Wills Hall. Nottingham has excellent social life, is on the whole safe [I'm from a town about 20 mins away]. And they have really good links with most firms.
But.... keep your fingers crossed for the phone ringing...