Some nice towns in the Peak District, and not to long a drive from Manchester area, Buxton ( stock up on the spring water for free!), Hathersage, Bakewell ( home of the Tart!)
In the summer the Peak can be beautiful ( and bleak in the winter!)
Don't forget Chatsworth House for all you Downton Abbey-ites! If you have kids, they have a petting zoo, and an adventure playground (if you don't fancy dragging moaning kids around), with enough claiming, sliding, zip wiring, to tire them out.
We went to Cornwall about 5 years ago and stayed in an Eco cottage in Mawgan Porth, the place was stunning, 2 minute drive and you were at the beach, the Jamie Oliver 15 resteraunt was nearby, good food, great views.
Padstow isn't bad either, and while down there, a trip to the Eden Centre was well worth it.