But to address your actual topic, it inspired a thought in me. While there's often no rhyme or reason why and how we choose your favorites, I do think that
style of play has a lot to do with it. A lot of my love of Roger is because of his play style. I won't go into all the superlatives - we all know his game well - but his elegance, grace, and diversity of talents stand out as especially relevant. It is basically an aesthetic preference.
I think the reason not many of the big guys are well loved, is because the all-serve, no-game style isn't very aesthetically appealing to many. Ivo is the most extreme version the game has ever seen (well, maybe Sam Groth), while Isner is a more functional version, and Raonic even moreso along the same spectrum.
But to go to
@mrzz's suggestion, I'm thinking we could start by looking at #1s and their heights...I think studies have been done. Also Slam winners. Anyhow, here is a list of current players at different heights, with retired all-time greats in italics:
EDIT: I've added some dimension to this list:
Active Slam winners in bold, Next Gen (b. 1994 or later) in green.
6'11": Ivo Karlovic,
Reilly Opelka
6'10": John Isner
6'8": Kevin Anderson, Jerzy Janowicz
6'6":
Juan Martin del Potro, Marin Cilic,
Alexander Zverev, Sam Querrey,
Karen Khachanov, Daniil Medvedev
6'5": Milos Raonic, Tomas Berdych
6'4":
Nick Kyrgios, Taylor Fritz, Stefanos Tsitsipas,
Marat Safin
6'3":
Andy Murray, Grigor Dimitrov, Jack Sock,
Felix Auger Aliassime,
Boris Becker
6'2":
Novak Djokovic, Jo-Wilfried Tsonga, Pablo Carreno Busta,
Andrey Rublev, Frances Tiafoe,
Stefan Edberg, Pancho Gonzales
6'1":
Roger Federer, Rafael Nadal, Dominic Thiem,
Lucas Pouille, Borna Coric, Hyeon Chung,
Pete Sampras, Jim Courier, Arthur Ashe
6'0":
Stan Wawrinka, Roberto Bautista Agut,
Denis Shapovalov,
Mats Wilander, John Newcombe, Ilie Nastase
5'11": David Goffin,
Andre Agassi, John McEnroe, Bjorn Borg, Guillermo Vilas
5'10": Kei Nishikori,
Jimmy Connors
5'9": David Ferrer,
Corentin Moutet
5'8":
Rod Laver
5'7": Diego Schwartzman,
Ken Rosewall
As far as I can tell, Marat Safin is the tallest multi-Slam winner, with Del Potro and Cilic being the tallest Slam winners. Becker is the tallest all-time great (if we define that as 6+ Slams). Don't know who the shortest is, but I'm guessing it has to be Muscles, at least in the Open Era.
You can also see how the weight of players is in the 6' - 6'2" range, and heights are trending upward.
I would define "tall tree" as 6'4" and higher. That seems to be the point at which altitude becomes more rarified.