Ireland ! Where / why ?

My good lady has told me that WE are thinking of popping over to Ireland for next summer's break ... blimey I haven't got over this year's yet !

Can anyone recommend sites / places not to be missed please ? .. both North & South if possible , the only probelm being that WE will probably only have 2 weeks & Ideally don't want to be packing up to move on every other day !

All suggestions welcome !

Many thanks folks !