My husband and I will be visiting Paris (first) and then flying to Dublin. In addition, we would like to see Galway, Dingle and Cork. We will be going home to the US from Dublin. After staying in Dublin for a few days, what would be the best way to visit the other areas. Renting a car seems the best, but also expensive. Do you think it's worth it? What about a bus or train?
You can certainly go by bus or train, but I have always rented a car. In some areas, like the Slea Head Drive in Dingle, you would need to find a day tour if you don't have a car. And relying on buses means relying on their schedules, not going according to yours. Galway is easily done by bus or train. You could possibly take a bus or train to Galway and then rent a car, if the price works better for you. Where are you planning to fly out of?
At first I thought that I would travel around Ireland via either the train or the bus, but found out that for what I wanted to do and see would cost just as much and take more time or the services just weren't available- I found a rental car the best deal. I knew that there would be times when I spotted something that I wanted to see up close or take photos and just be on my own time line and if I was on public transportation, the wouldn't be able to. The only hesitiation would be adjusting to driving on the other side of the car and on the other side of the road, but it can be done. We planned it so there isn't any driving in the bigger city, more rural roads, taking our time and enjoying the views and exploring Ireland our way. You can try to see what works for you with these two links: Trains - www.irishrail.ie Bus - www.buseireann.ie Have a great trip and safe travels!
One thing to consider is to fly to Cork from Paris, and leisurely work your way from western Ireland to Dublin. Then return the car in Dublin and use mass transit.
Mark has given you good advice. Fly from Paris CDG to Cork on Aer Lingus. Pick up a rental car at the Cork airport and head for Dingle, then Galway, then Dublin. You won't need a car in Dublin itself, but you could use it to visit Newgrange/Boyne Valley or Glendalough/Powerscourt Gardens/Wicklow on day trips. Or see either one or both of those areas via tour bus.