My vote would be for Bath, without a doubt, but it depends on your preferences.

We were in Bath a couple of weeks ago - extremely pretty, and plenty of sites to keep you occupied.

If you go there, make sure you see the Bath Abbey, the Roman baths, Jane Austen museum, the Royal Circus and Royal Crescent, and the open house at No. 1 Royal Crescent. Add to that the Pulteney Bridge (one of only two bridges in Europe with shops on it)and the river running through the city. All so very old and historical. A bus tour would put it all in perspective, but Bath centre is quite compact, so it can be walked quite readily. Wherever you choose, have a great time!

Cheers, Peter (An Aussie living in London)