We've done indirect flights with Continental, American and Delta, connecting in Newark, Chicago and Atlanta respectively.
But we're about to try Aer Lingus, Birmingham-Dublin-Orlando. They also offer Orlando via Dublin from Edinburgh or Manchester. We usually fly from Manchester but it's a long wait in Dublin on the way home, so we're going from Birmingham instead.
Hopefully everything will be up and running in the new T2 at Dublin so we should clear US Immigration and Customs there rather than on arrival in Orlando.