I have looked through the responses and either missed it or there was not a suggestion(s) of best hotel/ B&B in Conwy. I will be drifting from Cardiff and spending 3 or so days in Conwy as a base in the north. Thank you in advance!
The Porthmadog area would make a more central base for NW Wales if using a car.
James is usually spot-on, but we stayed in Conwy at the Castle Hotel about a week ago and really enjoyed it. If you will have a car, try to park across the street at their car park. Otherwise you drive thru the archway to the car park the back. If you have problems, run inside and they will help you. We stayed there 3 nights and drove around to several sights during the days. We enjoyed the town in the evening.
We stayed at the Gwynfryn B & B last month, in late May. I've seen others mention it on the Rick forums so I think it's pretty popular. It is centrally located in the middle of the city, is clean and tidy and nicely decorated and has a generous breakfast and is reasonably priced. The owners allowed us to store our bags past checkout so that we could visit the castle before picking up our car. It's a very pleasant place to stay. It's next door to the police station but there was only one incidence of sirens while we were there. You park just outside the city walls, so you should follow their provided arrival directions for dropping off luggage before parking. BTW there is a well regarded Italian restaurant just next door (Alfredo Restaurant) that smelled amazing, but you need to make reservations in advance. We arrived around 6:30 and weren't able to get a table until 9:00, so we went elsewhere.
We were originally going to stay at the Bryn Guesthouse in Conwy, which is just outside the city wall. Conway is so small that we're talking just a matter of perhaps 3 blocks distance between the Gwynfryn and the Bryn, so being just outside the walls is not an inconvenience in terms of proximity to sights and restaurants and may actually work better if you're taking day trips out of Conwy. We didn't stay there because they were completely booked, but Bryn also appears to be highly rated.
We stayed in Bryn Derwen Guest House in Conwy. Very enjoyable. Just a short walk from the train station.
I second the recommendation for the Bryn Derwen. Great location. Rooms are super clean and the beds are very comfy. Fantastic breakfast.
Didn't stay at the Castle Hotel but locals told us they have the best food in Conwy and we ate there twice. Highly recommend the fish pie!!
Thank you the suggestions. Unfortunately, all the suggestions are full while I will be there. So, I have 4 nights at Bryn Derwen in Llandudno. I will have a car so will be able to visit Conwy.