Hi Chris,
We went to the Plassey a couple of years ago It was an excellent site and at that time it did have a small bar which was reasonable priced and if I remeber right it wasnt a bad pint. Just a couple of points though if you do decide to go to the Plassey wait for the brown road signs directing you to the site as you come down the dual carriageway (A483) dont follow your sat nav it will take you through the centre of Wrexham which is what I did not very pleasent as there were loads of roadworks and quite narrow in places, also on arrival on the site there is a long drive with speed humps careful over them, then at the top of the drive assuming it hasnt been altered is a sharp left turn to the site office, make sure you take a wide swing out in order to get round watch the caravan through your mirror on the passager side and take it steady.
Or you could try Bon-y-Wendon, Llanddulas its a nice site a easy drive down the 55 the site 1 minute off the A55 and you are there they pitched my van for me with a small tractor just be aware of traffic noise from the A55 and trains (they dont run all night) that run past the site although these never kept us awake. Just one other negative watch the wind if you have an awning as theres no shelter from the sea, I had my awning wrecked here but it was October at the time but all in all a nice clean site.
Cheers Muggler