When I first obtained a camper van I headed for the highlands of Scotland. I love the mountain regions of the U.K. and I especially love the Scottish wilds. As a bonus you can pretty much camp anywhere as long as you don't obstruct the highway.
I'll be honest, I think I did more driving than anything else (I'm sure there's a bit of gypsy in me), but sights such as these are common once you get past Glasgow and Edinburgh.
MY favourite place to take a rest was definitely a small campsite named 'Portnadoran' not far from 'Fort William'. It was right on the coast and the view over to the Isle of Eigg and the Isle of Skye are out of this world. We stopped of at Loch Lomond in the south on the way through which is where the sunset shot was taken.