In terms of drinks memorable for fine barcraft, the honor goes to Milk and Honey, a speakeasy in SoHo/Chinatown. The best of everything, made with care. We all ordered one drink, and then let the bartender riff from there. Best Negroni I've ever had--the waiter mentioned an unusual vermouth that gave it the kick. Even my girlfriend's Pink Lady--not usually a "serious" drink--was killer.
For pure memories, though, it get no better than having martinis with my grandfather at a steakhouse. Well-made, but nothing fancy--Tanqueray, dry, anchovy-stuffed olives. I mark it because it was the first time I ate a raw oyster, and I believe the last time he was well enough to leave the house. A very good evening.
"You know what's right with this world? Nothin'!"
-Oscar, "Grouch Anthem"