Which fight today would add most to Mayweather's legacy?

He should of fought Brooks at Wembley this month; would have been huge.

 

Golovkin

Ulike Pac who most legit boxing fans knew was too small for him this is a far greater challenge.

Mayweather just fighting GGG win or lose would be amazing

 

It kinda depends.

At the moment lineal MW championship makes most sense.

In terms of legacy we would need to be able to go 10 years into the future and look back. If Floyd were to face GGG at full 160 limit and win, then GGG still went on to have the sort of successful MW and maybe SMW career many now predict that would be worth a decent amount more IMO.

Lineal MW title sounds great and would add to his legacy but boxing people who would be evaluating it would know the real story, that it was being held by a 154 lb'er who got lucky enough to face a shot one-legged Sergio at just the right time.