What is the best way to travel from Dublin direct to Shannon? I have checked flights, but the times are not good.
I'm not sure what you're trying to do but here goes. The best way is to rent a car. If you are committed to public transportation, there is a bus to Galway and a bus to Shannon from there. You'll spend about 5 hours driving and probably 8 or 10 doing the buses.
Try www.jjkavanagh.ie or www.buseireann.ie for bus schedules from Dublin Airport. Bus will take from 5 1/2 to 6 1/2 hours depending on route.