Can recommend Kilmahon House as a posh B&B in Shanagarry, East Cork. Excellent welcome, afternoon tea, breakfast is class.
You can stay in the light house at Loop Head, County Clare.
Parknasilla Hotel in Sneem, County Kerry is pretty good too.
Derrynane Beach in south Kerry is magic apparently.
Dingle is cool but will be heaving with tourists and is pretty €€€. Nice pubs though and generally good music.
If if you want to stay away from touristy places then stay away from Killarney town but the national park around it is pretty damn nice
What kind of stuff are you guys into?