I'm biased of course, but my vote goes to Lancaster
my "ride from home" routes include:
2 national parks; Lake District - loads of quiet lanes if you know where to look.
Yorkshire Dales - the western dales, particulary Dentdale (the best cycling valley in the country...)and its associated climbs.
AONBs Forest of Bowland, my personal favourite, outrageously beautiful scenery, classic Tour of Britain climbs, and there's virtually no traffic as everyone rushes past to the honeypots of the national parks mentioned above.
Silverdale/Arnside AONB.
Lune and
Ribble Valleys
Beacon Fell and the Fylde coast
Off roading including Grizedale and Gisburn Forests
Lancaster Canal.
Lancaster itself is a "cycling demonstration town" which means we've had lots of new lanes, junction improvements etc appear recently
Active cycling scene with Road, CTC, TT clubs and other groups
Salt Ayre circuit for traffic-free racing and TTing
West Coast mainline blah blah blah