I can think of several equally memorable bird moments - all different. -- E.g.
-- Standing up to my knees in a marsh in the dark, shining the flashlight in the direction a peculiar "keek-i-dee" sound was coming from, and having a Black Rail stare back at me for about 5 second before it "melted away".
-- Being surrounded by flying Whipoorwills and Chuck-Will's Widows at night in a clearing in a pine forest, with the stars shining overhead.
-- Lying on a roof in Cardel, Veracruz, Mexico and watching nearly a quater of a million raptors drifting overhead.
-- Finding and photographing a Mississippi Kite over my cottage - lifer for me, and first record for the Province.
-- Finding and photographing the Provinces first documented Fieldfare.
-- Seeing a Ross's Gull (me too) - I was in such a hurry to get my camera I knocked over my tripod and bent the end of my scope!
-- The whole experience of Tikal, Guatemala, with its magical ruins, fascinating history, and wonderful birds
-- The sheer terror the first time I ventured near an active N.Goshawk's nest on my own, and experienced Mom's ferocity in defending the area.
-- and many others.
-- All the great moments of companionship, friendship, and shared excitement with my birding friends, when we find, or ID, or confirm, something good. All the above experiences were shared with other birders (sometimes by cell-phone at the time!).
Cheers - Richard