Ty Gwyn at Mynt

Coastal site just outside Cardigan. Not been yet, but hope to

For
Views, views, views
beach
sunsets
beach kayaking

Against
Think its a long walk to the nearest pub/hotel

Llyn Gwnant - Snowdonia

Large activity based site in Snowdonia. No booking, but very large . Nearest town is Beddgelert

For:
great views
Campfires
At the foot of Snowdon
Pizza and beer onsite
Kayaking on site

Against:
can be windy as in the valley
No pub, but Youth hostel sells beer 1 mile away
Difficult on public transport

The Tavern inn, Kemble - GL7 6AX

Lovely pub with a campsite in the garden. Right next to the train station and on the edge of the cotswolds. 

Very basic site, but the pub garden as lovely views, and there are other nice villages nearby, and the Cotswold water park for sailing and the likes.