Over the years the best that my wife and I have had were either in Ireland, or Scotland.
Not frozen, not farmed, but fished (nets) local out of the cold bay waters.
And the best way to cook them is grilled, simply with nothing added. Perhaps a little sauce on the side but nothing on the prawn itself.
Served on airlines ? Yes, Well ..... I'll be diplomatic and state that nothing beats fresh grilled prawns, or shrimp out on the beach or quayside.
On this we both agree. When it comes to shrimp around the world, we differ. I prefer head-on, and my wife head-off.