I'll go, although my pool of big wins to pull from isn't great lol.
1) Win over #4 Pitt in 2011 at MSG the easiest choice: Still remember watching it with my Dad. We took a timeout before our final possession and my dad said "Hardy is gonna win us this game". Very good call by him. Atmosphere was electric even just watching on TV.
2) We had a win @Xavier during Dom/DLo/Greene's senior year that really got us off the bubble and put us in the drivers seat to make the dance. I remember Marco Baldi a JJ poster was over here during that time and I made a bet with him that if St Johns won, he would have to leave the site forever. If Xavier won, I would have to leave the site forever LOL. So there was some personal stakes for this one too. Even though we ended up calling off the bet before the game, I still just had this good feeling about this one. No one thought we could win at the Cintas Center. We went in there. Sir Dom was electric. We don't talk enough about the jump that dude made in his senior season. He really struggled during his career here, finding his place and his role. Senior year, he had the freedom to just be unleashed. Do everything. Even though I remember that win fondly, I believe DLo tweaked something in his leg that game that never really healed for the rest of the season.
Loss I still can't get over - Coach K's 1,000th win at MSG. We had that freakin game. Had it. We were throwing haymaker after haymaker. But just could not close in the final 5 minutes. Still makes me so mad. Tyus Jones b*tch ass stuck his leg out on a couple three pointers. This was back when refs were consistently falling for that. Flipped the game