there are some fantastic places to stay in wales.
St davids is a gorgoeus little seaside town, upmarket, no honky tonk, but still settled in its ways. It is very close to the ferryport and has whitesands beach, very picturesque.
Cardigan bay, up along the west coast, is also very good, with well cared for villages. There is a coastal path along most of wales.
Swansea is not much really, but the gower peninsula has a great hotel and fine restaurant ( fairyhill), and some great long beaches, with large sand dunes, great surfing, kiting and a good place to watch gliders and kite surfers ( worms head, llangennith beach). A village beside Swansea, mumbles, is twinned with Kinsale. Not as energetic, bit still nice to visit. Caswell bay is a sheltered and well serviced beach nearby, beyond mumbles.
Cardiff is a good spot. Plenty of good restaurants. The best there is Patagonia, a small steak house run by argentinians, steak and venison that is the best i have tasted anywhere. The bay is OK to go eat in, lots of chain restaurants. Cardiff castle is a good visit.
( I hate the way Cardiff Bay is filled in. Tidal movements gone, spelt disaster for the wading birds and now they pump air into it to stop eutrophication, not pretty, dublin city plansters, beware!).
Another nice trip is up towards Hay on Wye and Abergavenny, much more anglicised but really well cared for villages. The forest of Dean on the English border has some great cycling.
The Rhonnda heritage park is good if raining, really shows the misery of mining life. Also good mock up of going down a coal mine.
I spent 3 years there. never got up to north wales much though. PM me and I can send you on more details.