I don't know whether to laugh or cry at the blown up comment.
Ireland is a very beautiful country, but unfortunately the public transport is pretty awful, so if you want to see what it has to offer, you are probably going to need to hire a car.
If you hire a car, thankfully the country is small so you will be able to see lots of different places. If you would like to stay in one place, then Galway is very nice with a good mix of nightlife in a very small city, with nearby beaches and countryside to go and explore. If you really want to get cut off the grid and sit on becahes, then maybe Achill Island in Mayo (Photo) is pretty nice. It is quite isolated but is a short-ish drive to Cliffs of Moher and things like that. Good weather will make an excellent time in Achill.
Also, I love Donegal in the North West, but that is prob because it is reasonably close to where I live and we go there a lot.
Kevin
EDIT: An seriously, the North is nice now. You should check it out, maybe ot Belfast because it is like pretty much any other city in the world, but like Blowdart suggestions, the Giant's Causeway and the Glens of Antrim are worth a look-see.