try and get over to the west side if you can. There is good stuff to see over there. Arann Islands are def worth a trip, so is Bantry but that might be a bit tight with 6 up.
I'd recommend Kilkenny but not Waterford, they will charge you for your pax and there isn't much to see there!
There is a few things to see in Weston (Dublin) too and you are less than a half hour cab ride from the city centre.