Reputable tour companies for a trip to Ireland?

Look at Brendan (owned by the same parent company as Trafalgar but specializes in Ireland). I’ve also heard CIE Tours was good for that destination.

we just traveled around northern ireland in a rental car.. airbnb's.. it was easy on our own..

I did a tour with Abbey out of Canada 2 years ago. It was the perfect balance between guided tour and free time to roam. We generally were done with tour things by mid afternoon and had evening to explore. We had breakfast every morning and 2 dinners. No extra excursion fees. Hotels were 4 stars.
This past spring I went to Italy with trafalgar. We saw a lot but nothing was included. It was roughly an additional 1200 euro to be included in the excursions. The tour guide was a hard sell. She made us feel that if we didn't do all these things, we'd be missing out. After all, you may only go to Italy once. In some ways she was right. I am happy we did it. Everyone on our tour did all the excursions too. But I don't feel it was clear what was and wasn't included. Maybe they are dif in Ireland. On a positive note, they were very organized. We stayed at some nice places and really saw all the highlights that there was to see in Italy.

We did a package with air fare, rental car and hotel bookings and it was amazing. I want to go back so badly. I was worried about driving but it was such a good decision. We were able to do and see so much.

We did some tour company and some on our own during our last trip to Europe. I liked the tour aspect, because they arrange everything and move at a pace fast enough to see all the touristy highlights. Plus, you have an expert along to ask questions and who can add to the topic at hand. I also liked the part on our own because we are able to get off the beaten track and see things we wouldn't have seen on the tour.

In Edinburgh, I took a picture of a tour bus because I was so impressed with everything I saw. It was CIE Tours International. They seemed to be taking great care of their travelers, the ages were diverse, and everyone looked happy. Oh - and they were in the same hotel we were, which was really nice, as opposed to our student tour housing (which was perfect for students, but not quite as nice as the adults would have liked!).

Our friends used Monograms for their European vacation and highly recommended them.

I'm not sure what kind of tour you are looking for, but our family has done 4 Backroads vacations. They are active vacations -biking, hiking or multi-adventure, and we have gone places where it was more about seeing the area than learning about history (Patagonia, Banff/Jasper, Panama), so that may not be what you are looking for. However, we highly recommend them - they have an older teens and 20s and we have had great folks on all our trips

I did Insight around Ireland. It was amazing. Royal Irish Tours offers self drive packages w car, hotels booked along the way and w a map/driving directions.

My husband and I did an Irish Supreme Tour with CIE Tours in May 2018. It was very well planned and skillfully led and we had the best time. I believe the tour capped at 25 people (we had 23) which was a very nice size, and much smaller than some of the other tour groups we saw in passing. Our guide and driver were excellent and we learned a lot from them. The itinerary was a good mix of sight seeing at major attractions as well as activities where you got to meet with one or two local people in a small venue, plus there was flexibility so you didn't have to join an activity if you wanted time on your own. It was our first time in Ireland and I appreciated letting the tour company take care of everything. We will go back to Ireland, hopefully next year.