The answer depends on how you weigh impact at UM, team success at UM, significance to program / history, and ultimate nfl success, if that counts.
Example: LB: Morgan was the most decorated LB in ncaa history. Helped rebuild the program. No title. No canton. Lewis came after the decline had commenced, left early, no title, but goes down as the best defensive player ever, imo. Barrow was first team AA, top dog on best LB crew ever, won 2 titles iirc. Good nfl career. D. Smith was 2x AA, also key to title team, also good nfl career. I put none in a top 5.
Example 2: DT: Sapp technically won a title but it was his frosh year. He goes on to be unanimous AA, nagursky, lombardy, big east dpoy, nfl HOF career. But Jerome Brown was more important on totle teams at Miami, and helped build the brand, and was on his way to a Canton career (2x first team all pro his 2d and 3d seasons) before dying tragically. Maryland and Kennedy were 2xnc, Maryland more decorated in college, in cfb HOF. Kennedy in Canton. I give nod to JB.
Example 3: S: Evrryone talks reed and ST. There’s a reason the name blades is famous in Miami. Bennie was 2x AA, NC, Thorpe award, CFB HOF. He had the best college career of any UM safety, imo. But reed was close, should have won Thorpe, and obviously did it in the nfl also. And ST was maybe the best of the 3. I don’t see how you tell the story of the U without BB.
QBs: Kelly put us on the map amd is in Canton, kosar won first title, vinny amd gino got heismans, walsh and dorsey just won. Can make arguments for several of these guys.
McKinnie was the best LT I have ever seen in cfb. Special hat tip to leon searcy for being a 3XNC and AA. Note E. brown gets over-looked a lot but was on ‘84 title team, was a first team AA and left UM with all the receiving records.
My top 5-10, weighting play at UM (including major awards), significance of teams at UM, and contributions to program st UM with only a bit of NFL credit:
D: Hendricks, B. Blades, Reed, J. Brown, Sapp // ST, Maryland, Morgan, Lewis, Barrow
O (non-QB): McKinnie, Irvin, E. Brown, Wayne, Foreman
QB: Kosar, Kelly, Walsh, Vinny T., Toretta
Tough calls: Anderson, Edge, Andre, Rolle (very under-rated - no one threw his way).