Well from the period of 1979 (when I started watching) to 1995, BR (Before Ray), I would go with:
1. Donyell Marshall
2. Chris Smith
3. Corny Thompson
4. Earl Kelly
5. Cliff Robinson
6. Scott Burrell
7. Tate George
8. Nadav Henefeld
I saw Chris Smith play in high school a lot, both in actual games and in pick up games at Harvey Hubbel Gym at the U of Bridgeport and in the summer leagues at Wolfe Park in Monroe. He was the best and most entertaining high school player I ever saw. One of my best memories was seeing a pick up game that included Chris Smith, Chris Watts, Marvin Saddler and Frenchy Tomlin, all of whom played D-1 college basketball, at the Hubbell gym.
However I give the nod to Donyell mainly because of his back to back 40 point games and the show he was putting on at the end of his sophomore year. Unfortunately it ended badly for Donyell when he missed 2 FTs which cost UConn a game vs. Florida in the 1994 NCAA tournament. That had to be one of the more disappointing NCAA losses for UConn because they had the better team and they win if Donyell makes either of those FTs, but he missed both. I still have him at #1 though.
Honorable mentions on these lists should go to Lyman DePrest and Rickey Moore. DePriest was in my opinion the most versatile lockdown defensive player in UConn history and Moore was the best defensive guard in UConn history whose feats shutting down Allen Iverson in the 1996 Big East Championship game and forcing the Langdon travel in the 1999 NCAA championship game are now legendary. DePriest was a 6'6" wide bodied power forward but he could cover smaller, quick guards like Dana Barros, for which he achieved significant fame during the 1988 NIT championship run.