Positive recommendations for car rental companies in Ireland

Last Spring, we rented from Dollar (best price after looking at many other companies), picking up at the Cork airport and returning at the Shannon airport. It was a small Seat Ibiza compact, and went pretty smoothly.

We didn’t buy any of their collision insurance, using our Visa card’s coverage instead, which they wanted to see in writing. Visa mailed us a letter confirming their coverage prior to our trip. The one thing that wasn’t perfect was signage at both airports. At Cork, the signage for car rentals sent us to the right, and the desks were far left. But that would’ve been confusing no matter what company we used. Then when we wanted to return the car, and followed signs for Dollar’s return location while approaching Shannon Airport, the signs indicated a different direction for Dollar than for other companies. We got to the supposed building and found a sign taped to the front door, saying that office had stopped being the return depot, and to park in the lot with everybody else’s return cars, and turn the keys in inside the terminal. It would’ve been nice if the signs approaching the airport had not sent us elsewhere. Fortunately, we had plenty of time to make the extra side trip before going where they were now receiving the cars, and make our flight..

No extra fees, no issues with the condition of the car when we returned it, full tank when we picked it up (and when it was returned). The Ireland trip before that, in 2018, picking up in Galway and returning in Dublin, we used Enterprise. That was an excellent experience. Enterprise was really expensive, though, last year.

Many here (ourselves included) rely on AutoEurope for car rentals in Ireland. They offer competitive pricing, great customer service, and their insurance options are fairly priced if you don't have one of the premium credit cards that provide coverage. I trust their reviews of the various companies too.
One suggestion would be to continue on to the Kerry airport near Killarney after landing in Dublin - RyanAir offers two cheap flights per day. Once there you can choose among a half dozen rental car concessions, including all of the usual suspects: Hertz, Avis, Dollar, etc. You'd then have the option of doing a one-way rental, exploring the South and West of the country at your leisure, dropping the vehicle at whichever final destination destination you choose.
Know that many (if not all) of the companies now impose a one-way drop off fee but it's not particularly onerous and will likely be worth the extra cost just for the convenience involved .. as long as you're returning the car within the Republic that is. A one-way rental between the Republic and Northern Ireland will trigger an international drop fee which is usually quite expensive.

I always start by looking at AutoEurope to compare rates. Using the Irish version of their website can sometimes get a better price AutoEurope.ie . Our rental was with Alamo and they were excellent to deal with. Check details carefully--some companies charge a surcharge to cross into Northern Ireland, Alamo did not. And AutoEurope caps the second driver daily fee.

I've rented twice from Conn's Ireland, https://connsirelandcarrental.com/. They have multiple locations throughout the Republic and Northern Ireland. Each time we rented from their Dublin South Circular Rd. location and returned to the Dublin airport. There was not a one way drop fee but perhaps that was because the locations are so close. I don't know if, for example, you rented from Shannon and returned to Dublin. They are a Hertz franchise. Both times I got the car I wanted- a compact automatic. Everything was done and completed promptly and I like the fact that they have a US phone number which you can call if you have questions. I did call once and left a message. My call was returned within 15 minutes.

We used Avis when we were there and it was fine.