Federer is probably the greatest, but I must add that the big four of Fed, Nadal, Djokovic and Murray have had a fantastic level of consistency for many years, with some great rivalrys. We are very lucky to witness this era of tennis because I haven't seen anybody who could step into their shoes just yet when they eventually wear down or retire. Del Potro looked a likely challenger but injuries have plagued his career and Cillic has underperformed too.

Pete Sampras.

Federer for sure.

Poor feds :(

Objectively, Federer. Though my favorite was Bjorn Borg.

No love for Super Mario?

Nothing, and I mean nothing can best Federer. He's 33, isn't he? And still #2. It's THAT incredible.

Nadal is my favorite, but I don't consider him "greatest male tennis player" quality. For me, that's between Federer and Sampras. Roger's backhand looks so effortless and graceful and he's very well rounded. Pete was a monster in his time too and who didn't love his jump shot? lol

Serena...

Boris Becker!