Where to stay in North Wales

Will you have a rental car?

Car or no car - that is the vital question? Be sure to visit >https://www.nationaltrust.org.uk/bodnant-garden
(The picture you see now is a winter view. In mid May it will be spectacular and the famous laburnum tunnel should be in full flower).

If you will have a car, I recommend Agar House B&B in Llandudno. It is in a good location, has friendly hosts, is comfortable, is reasonably priced, and serves a delicious breakfast. You can walk to the east shore, west shore, shops and restaurants. It was a great base for exploring North Wales. Such a beautiful area! We visited the places you mentioned except for Bangor.

http://www.agarhouse-llandudno.co.uk/

https://www.tripadvisor.com/Hotel_Review-g190724-d569859-Reviews-Agar_House-Llandudno_Conwy_County_North_Wales_Wales.html

Yes, we will have a car

OK - so that opens up a big area in which you could stay. For a central location, the Porthmadog area is quite good for getting into the scenic areas - though the town is nothing special. It is also the place from which two scenic narrow gauge railways run:> www.festrail.co.uk It is also near to Portmeirion - well worth a visit - and it also has upmarket accomodation.
One of the cheapest places to stay in Porthmadog would be the Travelodge - which can be hot due to lack of air-con and it is in a small industrial park.

If you want something with more local appeal, consider staying on a farm - but check out the road access on Google Streetview first - as you should with all accomodation: > https://www.farmstay.co.uk/PlacesToVisit/Wales/NorthWales

Don’t bother with Bangor. Consider a trip up the Snowdon Mountain Railway - if you can pre-book the day before knowing that the weather will be good. The coast road down to Harlech (Castle) & south to Barmouth - is nice. Map >
https://www.google.co.uk/maps/@52.9583403,-3.9571572,91414m/data=!3m1!1e3!5m1!1e1

James, what would you think of Betws--y-Coed as a good base for the OP's suggested locations? We used it our base in 2015 with a car to visit many of those same places and found it worked well.

Yes, I think that Betws-Y-Coed would work well as it is a very central location for the main areas of interest. The only downside is that the roads through the village can be quite busy.

We enjoy Llanberis. It's a small town, has several cafes and restaurants, and a couple of little grocery stores.. The Snowdon Railway starts from there, it's not far to get to Caernarfon Castle , Conwy or Beaumaris, or even the ferry to Dublin. Also close by are the National Slate Museum and Electric Mountain. Last time I rented a delightful cottage just off the main road, for my adult son and myself. There were more bedrooms than we needed, a full kitchen, and even a washer and dryer. I reserved that through Sykes Cottages, and I was able to book the cottage for three nights.

Thanks for the replies. Looking more in depth on your suggestions. You have given me a great start on planning my stay.

Has anyone here stayed at The Gladstone in Dwygyfylchi, near Conwy?
PG

Here's where we stayed in Betws-y-Coed and we were very happy with it. (And they do have a few family rooms where three could fit)

https://www.gwydyrhotel.co.uk/

Pleasant and very clean with recently redone bathroom. Decent parking in the back and you can just walk to anything in the village you need. Rooms on the front will have some traffic noise from the main road through town.

We stayed in Betws-y-Coed in early May of 2018 and thought it was perfect for our three day stay in North Wales. I heartily recommend The Ferns Guesthouse. www.ferns-guesthouse.co.uk/ The hosts, Mark and Sarah, were extremely helpful in answering our questions and providing information about North Wales. The guesthouse is located on the main street of the village which made it easy to walk to the shops and a good selection of restaurants. With a car, you could easily drive to Bodnant Garden, Conwy, Snowdonia and a variety of castles.

We stayed in Caernarfon at Victoria House B&B when we visited that area.

We also stayed at the Victoria House B&B. It is very nice, the breakfast is excellent, and the host very helpful and pleasant. The location abuts against the city wall, which you can access!

I stayed at the Premier Inn in Caernarfon and the Castle hotel in Conwy.

We spent a week in Wales back in May. I would recommend that you look at Betws-y-Coed, Llandudno or Llangollen. You can't Snowdonia National Park.