Stratford is a clear favourite in my mind, though I've seen but not used the HI.

HI Winchester is lovely though mainly if you're on your own for work, as you'll be well looked after but there's little to do without a drive into Winchester itself (which is also very nice)

Tamworth's OK, and near to Lichfield which is nice, but there aren't a whole lot of truly rural options really as they don't suit a chain hotel's model very well