ways.

That being said, I think you have to start by asking if they were the best in the country at their position at some point during their career. This eliminates Collie as I don't think he was ever the best WR in the country.

McMahon, Young, Staley, Detmer, Buck, Chris Smith, Pitta, Elewonibi, Marc Wilson, Bart Oates, Kyle Van Noy and Nick Eyre.

Then you need to decide how important longevity is compared to wins and losses and impact on the game. Adding all three of these together leaves you with just McMahon and Detmer. (Young as great for a year, Staley was extremely good, but didn't have the same impact over a career/season due to injuries, Buck was flat out dominant, but we went 8-5 in his best year, Smith and Pitta were great TEs, but I dont' think a TE impacts the game as much as a QB, Elewonibi, Eyre and Oates were both very good, but again I have a hard time with an OL compared to a QB, Wilson wasn't on the same level as McMahon and Detmer in "greatness", that leaves Van Noy who was extremely good but was on some good but not great teams).

McMahon and Detmer both played on elite teams (largely because of them), were the best at their position in the country, had their fingerprints on every game they played and were All-American for multiple years (Detmer a consensus All-American two years in a row).

Based on longevity, a Heisman (although McMahon was robbed) and what I consider the best BYU victory of all-time (Miami) I would lean towards Detmer.