Ireland is such a small island that you can cover a lot of ground in a week, and feel quite at home within two, but even with the best of intentions and all the energy in the world, you'll never see it all on a short visit.
To get the most out of it, you need to know at least in part what you want to see, and that will decide how you should travel. If your ideal Ireland involves wandering through the countryside, visiting small villages, climbing castle walls, hailing history from a ruined abbey, or finding yourself alone on a rocky beach -- you simply cannot do those things without a car. Out of the main towns, public transportation exists, but it's slow and limiting. Every major town has car-rental agencies, so give strong consideration to renting a car.
The next step is deciding where to start. That decision can be made for you by where your flight terminates. If you're flying into Shannon Airport, then it makes good geographic sense to start out on the west coast. If you're flying into Dublin, you might as well explore that city first, then either head up to the North and the ruggedly beautiful Antrim Coast, or south down to the Wicklow Mountains, Kilkenny, and the rolling green hills of Wexford and Waterford.
Still, if you fly into Dublin but your heart is in Galway, no worries. You can traverse the width of the country in a few hours (once you get out of Dublin's stultifying sprawl), so if you start early enough, it's doable. Just bear in mind that rural roads are not well lighted or well signposted, so driving at night should be avoided. It's too stressful, and being lost in unfamiliar territory, where it can be many miles between villages, is no fun at all. This is more of an issue in the winter, when it can get dark as early as 4pm, than in the summer, when it often stays light until after 10pm.
So taking all of these factors into consideration, the question remains: Where do you want to go? We can't answer that question for you, but we can give you some itineraries that we have used ourselves, which you might enjoy, depending upon your interests.
These might help you focus on ways in which you can orchestrate your journey so that you can get the most out of it with the fewest scheduling worries -- the last thing you want to do on vacation is to spend the whole time looking at your watch.
If you've never visited Ireland, Dublin is a good place to start, and the surrounding area holds plenty to keep you busy. If you have been here before, and Dublin and Galway are old hat, you might consider heading north, through County Mayo, County Sligo, and on to the exotic wilds of Donegal and the Antrim Coast.
Take what you find here, and pick and choose the parts that appeal to you, add in your own favorite shopping or scenic drives, and turn it all into a holiday custom-made for yourself.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.