The first was when BYU signed Shawn Bradley, Ken Roberts and Ryan Cuff and was a top 5 recruiting class nationally. The 3 never played a season together. Bradley went pro after his mission and Cuff transferred after his freshman year.
Then the LP3 + Yoeli Childs + Elijah Bryant had everyone expecting NCAA glory. They played only a season together and then things blew up with divorce, questionable early draft declarations and NCAA violations.
What might have been, but never was.