We fly to Orlando several times a year to visit family. Have flown various airlines but find Aer Lingus direct is fantastic - flew out for New Year, 9.5 hrs and just returned yesterday on a 7.5 hr flight. They often offer an upgrade to premium (not business) for an additional €200, which allows extra legroom.
It is usually a little cheapter to fly Continental via Newark or American Airlines via JFK or Chicago, but of course it takes longer. You can also do Delta via Atlanta and American Holidays do a charter during the summer months to Sanford Airport, which is about 55 mins north of Orlando.
Whichever way you choose to travel, you will find Orlando a lot of fun.