Guinness is too Dublin. Murphys and Caffreys out west :tongue:
The West coast is the big draw for tourists.
West of Cork, you'll be sure to go via Kinsale. Gourmet capital of Ireland, but damnedable to get parked in the town. Arrive early.
If you get the weather, Mizen Head on the extreme SW is spectacular. Nice cliff-top walk out to the point where you turn and look north up the west coast.
Cracking road up the mountain where you cross from Cork into Kerry. Caha Pass?
Bits of the Ring of Kerry are good, but for me it's overhyped. Dingle peninsula for one is just as good.
Clare is unusual, with the strange Burren landscape. You have Ailwee Caves, Cliffs Of Moher, and the house used for outside shots of Craggy island Parochial House!
Also Nagles of Doolin campsite is a great spot, right on the shore where the Burren meets the Atlantic. Famous O'Connors Pub 1km up the road in the village.
Galway lots of nice scenery and roads out in Connemara.
Cong on the border between counties Galway and Mayo is where The Quiet Man was filmed, if you're of a particular age
Doo Lough pass, on a loop west from Leenanne, then north, and back east to Westport is a lovely run too.
Achill Island in Mayo is fantastic in good weather. 'Atlantic Drive' road round most of it. It's all about the rugged scenery.
Donegal is about my favourite county. Described as 'Ireland in Miniature'. Pretty unspoilt as tourists concentrate on the SW of the island. Cliffs of Teelin 600m drop to the ocean. Stunning. You walk all the way along, or have a short stroll from the carpark just to take in the view.
Ballymastocker Strand near Portsalon much further north is a place I have trouble dragging myself away from. Stand on a empty beach, slowly spin through 360 degrees and it's all breathtaking.
As someone else said above, it's all about the coast in Ireland. Midlands haven't got so much to offer.