I think Kuerten and this is why. Pretty much all of the players had to face 2 very good players and the rest was easy. Kuerten had to face 3.
Chang (89 French) -- Sampras, Lendl, Chesnokov and Edberg
Sampras pre prime on clay, that is pretty easy.
Chesnokov 1 time semi-finalist, otherwise nothing.
Lendl was good and so was Edberg
Sampras (90 US Open) -- Muster, Lendl, McEnroe, and Agassi
Muster not that good on HC best is QF at USO.
Mcenroe past his prime for a very long time.
Lendl was good as well as Agassi.
Courier (91 French) -- Ferreira, Todd Martin, Edberg, Stich, and Agassi
Ferreira Not that good on clay 4th round best RG result.
Todd Martin not that good on clay 4th round best RG result.
Stich one time RG finalist but still not his best surface.
Edberg clay not his best surface 1 time RG finalist.
Agassi was good on clay but not his best surface.
Agassi (92 Wimbledon) -- Becker, McEnroe, Ivanisevic
Mcenroe WAY past his prime.
Becker not at his best anymore, but not that bad.
Ivanisevic was good at the time although he did have to wait a long time for his first and only Wimbledon slam.
Kuerten (97 French) -- Muster, Medvedev, Kafelnikov, Bruguera
Muster good on clay and won RG in 95.
Kafalnikov good on clay and won RG in 96.
Medvedev not that good but still 1 time RG finalist.
Bruguera good on clay won it in 93 and 94.
Safin (00 USO) -- Ferrero, Todd Martin, and Sampras
Ferrero not bad on HC but not his best surface either.
Todd Martin wasn't bad but not the best player around.
Sampras was still a very good player.
Hewitt (01 USO) -- Haas, Roddick, Kafelnikov and Sampras
Haas not bad but not that good either.
Roddick pre prime but still a good player.
Kafelnikov past his prime I think but still good.
Sampras was still a good player.
Djokovic (08 Aus) -- Hewitt, Ferrer, Federer and Tsonga
Hewit past his prime.
Ferrer not a bad player, but not that good either.
Federer good win.
Tsonga this final his only good result as of now, don't think he is that good.
Del Potro (09 USO) -- Ferrero, prime Nadal and prime Federer
Ferrero past his prime and not his best Surface.
Nadal not his best surface, SF best result which probably will not change in the near future.
Federer not in his prime, but still a good win.