I don't know if you are able to use Tripadvisor in the States. But that is a very useful tool to have when choosing a hotel. The customer reviews are well worth reading. I noticed that the Sligo Park Hotel has a good track record. Part of it overlooks the Benbulben Mountains so it will be spectacular scenary, my ancestors had a farm at the foot of that mountain, still in the family but only used for horse grazing now. You know how it is in Ireland!!
Anyway they're be plenty of lovely hotels depending on whether you want to stay in town or the surrounding area.
Good luck in your search. Its makes me want to return to that beautiful country and I only went last year!