if you want a site with nothing but basics, there is one called medowbanks. It has toilets, bathrooms, laudery, little shop and a tiny little games room with a pool table. It has a lovely river to walk along and a little park just outsside. Will say it has statics there too though, and beach is a drive away.
highly recommend mudeford or highcliff but only stayed in statics though
I did really like Christchurch in the Forest of Dean.
However the toilet facilities aren't great and a bit past their sell by date. You have to time a shower for hot water, the drains often couldn't cope with the amount of water. Much as I like standing in a pool of water ;) luckily I no longer have a toddler. They're kept clean tho and the staff did extra cleaning if there was a complaint.
There was a Costa Coffee machine in the shop but over a May bank holiday and half term it never was in operation. We asked several times when it would be fixed and kept getting the reply that it wasn't working LOL The appearance of pain au chocolate and croissants was a bit erratic, seeing as it was a busy half term and bank holiday. I don't mind but my 7 year old kept hopefully going most mornings, lined up for 15 mins, then told they didn't have any that day. He wasn't best happy!
Oh dear that sounds as if we didn't like it, we did LOL It's just that we'd seen Costa and left the stove top expresso maker at home, I was gasping for a proper coffee by the end ;)