Prestwick is to Scotland what Shannon is to Ireland.
Both were designated by government as international gateways in areas of high unemployment. All International flights entering or leaving the two countries had to enter and leave via these two points hopefully generating money for the local economy. Fortunately that has now changed as regards Prestwick which is like a timewarp of the sixties.
Most Aer Lingus transatlantic flights call at Shannon on either the outward or inward leg of the journey
The airports I use most are Belfast International or Dublin.
I would have to say that my most favourite airports would be Atlanta in USA and Kuala Lumpur in Malaysia
Love many, trust few, always paddle your own canoe