Nicest place I've ever flown to was
Brac LDSB in Croatia.
In the UK, there are quite a few good places though many are PPR.
My only bad experiences in the UK were at Panshanger (where some "important" person on the radio demanded an overhead join with a RH circuit, despite not having any known traffic), and Stapleford/Wellesbourne where I would not fly on a sunny Sunday preceeded by weeks of bad weather, due to so many crazy people (often accompanied by instructors).