If you could make anymatchup from any era what would it be?

[CGM]

I'll do one for each weight class that way its easier.

Welterweight = Thomas Hearns vs Sugar Ray Robinson

Good one. I can think of a few others I'd like to see against Robinson, such as Leonard, Curry, etc. For sure Robinson's record is optically most impressive, but I'm not convinced that he is definitely superior to the best of other eras, in terms of boxing ability and what would happen in face to face, prime vs prime meetings. In that sense I don't think he is necessarily undisputedly the best. Too much weight goes to long extensive records with many fights. IMO.

[jmbtandy]

I think even fights that have happened or are about to happen but with both fighters in their prime

Mayweather v DLH
Calzaghe v RJJ
Vargas v Mayorga
Tyson v Lewis