We are dropping our rental car at the airport about noon on he 30th and will spend 3 nights. What transportation should we consider? We'd like to do the hop on hop odd bus.
Easy transport between the airport and city: Dublin Airlink.
I've used Dublin Airport taxis several times to get to and from the airport. I found them easy to work with and very accommodating, they were easy to deal with and had no problem with some late changes to our reservations: http://www.dublinairporttaxis.com/index.html
The hop on hop off buses were very convenient for getting around