We've been to Dublin twice and each time we stayed in Malahide. There are plenty of B&Bs there (with free parking) and it's only about 15 minutes from the airport. We used Malahide as a base for visiting Dublin AND making day trips. You could take the bus or DART from Malahide to Dublin if you want to see the city. It's also convenient for day trips to Newgrange, Trim or even Glendalough. Malahide is a pleasant seaside town with a castle. Although we did not tour the castle, we did walk the grounds and I remember there was a children's playground there.

Howth might be nice. Beside the sea. Good restaurants. Dart (light rail).

When are you going to Dublin? there usually isn't a problem with accommodation in the city at the moment.

Get off the flight out of the terminal onto the Belfast Bus for a couple of days. Kilkenny is as far as I recommend (Direct) off a redeye. Without knowing your dates (guessing the end of May so Bank holiday busy/pricey) and Itinerary as a whole its difficult to give best measure but leaving Dublin to the end might be an option or reversing your trip?? (all guess work)

Malahide is a nice option. You could also look into Dun Laoghaire to the south. It's a good location for a trip into Wicklow or Dublin.

Thanks, all - I think we've settled on Bray for that first night. Easy visit to Powerscourt the next day and relatively on the way to Kilkenny without a ton of driving after landing at 3pm.

(bad idea?)

I like Bray..For Accommodation the Esplanade is a typical Victorian hotel slightly dated but Clean, great staff an a good breakfast, front rooms overlook the beach, free parking on the road outside and handy for a quick walk up Bray Head after (or before breakfast) The Royal Hotel is nice enough but don't get a room above the swimming pool because the aircon crackles all night. The Martello would also be on the 3spot short list mid week has it's own nightclub so maybe nit best at weekends.