I've been to both countries, and they are both beautiful, but my personal opinion is that Scotland had more character. You could spend days exploring Edinburgh Castle alone. Aberdeen and Inverness are both worth a visit too. I still need to go back to visit Dunnottar Castle (near Aberdeen), the Orkneys, and more of the highlands.
Dublin has loads of beggar kids, but the west side of the isle is absolutely beautiful. Blarney Castle is a cool place to visit, but loaded with tourists. Star Wars is filming on Skellig Michael off the SW coast. New Grange is a world class archaeological site.
Lots to see and do in both countries. Lots of pubs to explore in both countries
