Good question. Some thoughts:
Khalid, at 5-10, keeping 2 offensive rebounds alive before Rip made his fadeaway to beat Washington.
Tate's game-winner to beat West Virginia in first round of 1988 NIT. A journey of 1000 miles...
Not a specific play - but Rip's 24 on 9-14 shooting against Gonzaga's box and one was arguably the most unheralded single-game effort in our history. He didn't have a single easy bucket - and carried us on a day his wingmen were awol. Specific play one round later: Rip double-clutch jumper vs Ohio State in semis as shotclock expired - killing a late Buckeyes run.
From 77-74: Freeman had a one-armed rebound and putback early second half when it felt like Duke was starting to take control (up by 5). Small moment, but it was a momentum-stopper.
From 2004: Denham hit a 3 late in first half right after Duke went up 10. We were in danger of letting it slip out of reach with Emeka on bench.
From 2011: The pass to Lamb to win title game. A forgotten play in the Kemba archives. Okwandu's late defense on Derrick Williams. And there was a no-look from Bazz in the finals vs Butler to find Alex for a layup, right after Butler went zone. That was in many ways the back-breaker - the final card up their sleeve did nothing.