Irelands biggest airport has been maligned in the past for its security issues, and delays. Having traveled through this airport more than a half dozen times, I certainly havent seen it to be much worse/better than other reasonably busy airports. Plus, it does have the advantage of being easily accessible by transportation means other than by car. Driving around Dublins airport is not as easily achieved. You are not only contending with driving on the left side of the road, but it can feel like a slow moving, chaotic parking lot along the arrivals level.
Instead, the bus and taxi options are the least stressful. The airport shuttle is better known as Airlink, and offers direct airport service from the main downtown arteries like Grafton and OConnell Streets. It costs 7 euro one way or 12 euro roundtrip and runs every 20 minutes
Taxis to the city center are easy to secure on the arrivals level and will run you approximately 25 euro.
The city bus is the least expensive option, but is also the slowest. The Dublin city bus number 41 does the route to and from the airport, and depending on the time of day can take up to 90 minutes travel time. The advantage is of course price, and you will be looking at doling out a fare of under two euros.
The airport itself is well supplied with ATM machines, and has decent shopping with affordable duty free prices. Certainly, many of the shops are well supplied with the kitsch you would expect in Ireland including plastic leprechauns, and blinking shamrocks, but there are also decent deals to be had on the quintessential duty free items such as perfume and alcohol.
It is important to note that Dublin was singled out as being a bit lax on security, but that has tightened up. Currently, all travelers are expected to remove their shoes. But other than being shoeless for a few moments, the rest of the security screening is not unusual, and lineups move at a fairly rapid pace.