We used to love spending the summer holidays at Ruda Holiday Park in North Devon (Croyde Bay, near Barnstaple). You can rent holiday homes/caravans or they have lots of camping pitches available if you're on a budget.
It a lovely area, you're just 5 minutes walk from the beach, which has great surfing... and if you walk a few minutes into the nearest village, there's a gorgeous clotted cream ice cream shop
. Plus, the site itself has a pool with a waterslide and rapids, a pizza place, a cafe, an arcade for the kids, lots of kids activities and evening entertainment - for both the kids and the adults:).
Luckily, it's not much like Butlins at all, although it is now owned by Parkdean Holidays, and depending on availability/accomodation that you choose, it doesn't have to be expensive (we always rent a pitch in the camping area rather than paying out for a holiday home).