I love Haven.
When my boys were younger we went to Haven sites at least twice each year. On the cheap! Low Season chalet or camping in our little dome tent. Fantastic value, half-price pitches and full use of site facilities.
I used to love little Felixstowe, because the site there is so close to the seafront. Pebble beach, alas, but a lovely traditional seaside resort.
Heacham I did not like. Too small and quiet, too few on-site facilities. Caister I love, Gt Yarmouth in general I love!
You are so making me want to go to the seaside again. But my boys are both grown and flown.