I work with a lot of people from other countries and they always ask where to visit. They usually want London, Edinburgh and Bath or Oxford.
I think we are lucky there are so many good things to see in the UK. In terms of experience I often point them towards;
A beautiful windswept beach (e. Three Cliffs in S. Wales or Bamburgh)
A seaside resort for amusement arcades, a pier and fish and chips
A castle
A Sunday pub walk (somewhere like Cotswolds or by a river so maybe Henley)
Punting in Oxford or Cambridge
A sport event (they usually pick football but I push rugby )
Avebury or standing stones elsewhere but not Stonehenge
A pantomime if near Christmas
A country fair in summer
An industrial city like Glasgow or Liverpool
Actually there's too much to list