I'm definitely an easily impressed birder too, but I did have a very special encounter this summer. I was walking the coast path in Cornwall in the south west of England (I'm a Brit). I had hoped to see choughs - beautiful small crows with lipstick-red beak and legs, which have recently made a comeback after being extinct in England for two decades - but I didn't expect to see dozens of them, calling boisterously to each other as they flew along the coast always in pairs. They have gone from being extinct to not even really rare. It's really good to see a bird whose numbers are increasing when the vast majority of species are going in the other direction :(