I think I was most pumped when I went to my first NT at D2 Armstrong Atlantic State in Tarkanian...I unexpectedly won the CT and believe my first round opponent was #1 seed SIU-Edwardsville, managed by the great coach_billyg.
Making it to D1 was big, but it didn't excite me that much, hopefully getting back next season to give it another go. I played in the very first season of HD in 2004...Dubuque in Naismith. I noted my 1000th HD win on here but that's not a big deal, but I also recently had my first/only 1st Team All-American and National Player of the Year (Jeremy Huynh Mount Olive, Phelan), so I was pretty stoked when I noticed that too.
Many others have bigger stuff to brag about, but I must say, I've loved this game since I started playing "full-time" in December 2009.