Rosewall already mentioned, and deservedly so. Here's a couple of others from the "way back machine":
Lew Hoad...even more "butter" than Rosie
Ilie Nastase...Grandpa Fed, but a head case
Vitas Gerulaitis...Hopman-infused game was a throwback to Hoad/Rosie
Johan Kriek...was courtside for his QF night match @Armstrong vs Vitas...never saw two guys able to cover so much court in one match...absolute classic!
Nobody beats Tomas Berdych 18 times in a row! Project 18 incomplete.