We only did 2 days, but had a fantastic time. Found a \link{http://www.churchstile.com/\fabulous little campsite} in the middle-of-nowhere just past the back-of-beyond in Western Lake District. Very quiet, but family-oriented; lovely clean toilets/showers, and plenty of children for the kids to play with.
The weather was wonderful too - very cold first night, but very little rain to speak of.
Unfortunately the freedom to explore and be adventurous went to ds2's head. So on the evening of day 1 on finding the swing bridge at the playpark a bit small he climbed up on the handrails and balanced ... or rather didn't!
None of us got very much sleep that night as he woke up sobbing every 30 mins saying how much his wrist and elbow hurt 
Fortunately the local A&E had him assessed, X-rayed, and plastered (broken wrist/query damaged elbow) within 90 mins of us walking through the door. So it didn't spoil our holiday, but he is rather subdued!