To avoid the tourist traps, come to the Western Lakes. A bit further to go, but well worth it. Stop in one of a couple of nice hotels in Ennerdale Bridge and visit two of the best lakes - Ennerdale and Wastwater (deepest lake and highest point in England).
If you don't want to go quite so far, Keswick is an excellent Lakeland small market town and a good base for touring, walking or whatever takes your fancy. Take the time to call in to John Norris' shop at Penrith, another fine small market town. Excellent shops there too but not too many of them, so a compromise for both you and the better half. Call in at Pooley Bridge, not too far from Penrith, a nice Lakeland village on the shores of Ullswater where you can take a steamer ride on the lake, either one way and a walk back or the round trip.
Ambleside, Bowness-on-Windermere and places nearby are absolutely lovely, but they are much more accessible to those living in the big cities of the north and so there's always loads of people and traffic on those country roads with people taking breaks such as you are planning. Especially at the weekends.
Enjoy.