hey, leave the spice girls out of this! *fondly remembers her youth*
To be honest, whether you choose Bristol or Warwick will depend on the type of thing you're looking for; if you would prefer to live within a campus where all the amenities are on hand, and most of your nightlife will revolve around your student union (not saying this in a pejorative sense, just saying), and which might be said to be safer, then go to Warwick. If you want a city university, where the accommodation and faculties are more spread out, but where there's much more nightlife and things to do without having to travel into the nearest city, then Bristol might be better for you.
I did visit warwick for the open day, and I have to say, i was rather unimpressed by the accommodation, and when our tour guide student said 'it's great; you can't go anywhere without seeing someone you know', I was instantly put off and wondered why that was said to be a good thing, but again, others may find this appealing.
As I drove through coventry on the way home, my dad (quite rightly) pronounced it a ****hole, and I think that was the final nail in the coffin.