How about St.Mary's, Isles of Scilly? On a good day the views on approach of the islands, beaches and crystal clear water make it look like the south Pacific.
Don't get too distracted though - runway lengths are 523 and 600 metres with interesting humps in the middle, and brake failure could have you in the drink!
Worst airport: Heathrow, considering its location in a "developed" country. T3 arrivals is a disgrace: Tatty, cramped, poor signeage, generally falling apart, and who selects those awful swirly-pattern carpets? How apart some signs in languages other than English?