It was a few years ago now but we went to Pooly Bridge in the lakes which was quite nice, thats if you dont mind the sheep been in the same field as you.
Park Cliffe at Windermere is nice, there's a stream for the kids to play in, also a games room and play park area. It's at the bottom of a big hill which you can climb to get a fantastic view of the lake. There's also a shop and small bar / restaurant. Another plus point if you have small kids is the opportunity to hire a bathroom with a bath, either for the whole of your stay or free of charge for an hour. My 1st gallery photo was taken at Park Cliffe. http://www.ukcampsite.co.uk/sites/reviews.asp?revid=2241
Stayed at the National Trust campsite at Wasdale Head,north shore of Wast Water,for a week last May and it was brill.
Just the campsite,pub with good food and brews its own beer,couple of farms and a chuch and loads of great walking all round.
Going back this May
we stayed at park cliffe in windermere a couple of years ago, and would echo what camper jan said about the site. location was good and plenty of hills to hike up and take in the stunning scenery.
We've been to the C&CC site at Ravenglass and the CC site at Braithwaite Fold at Bowness on Windermere. Both are very good sites but the Braithwaite Fold one is a particularily good location.
We've stayed at The Quiet Site at Watermillock near Ullswater many times. Lovely clean site with a bar in an old converted barn with a log fire which was nice even in Summer. Also adventure playground and games room for the kids, highly recommended