Well, for me I have two different sets of greatest athlete. One is for players of games which I call greatest athlete (greatest fame, stats, etc)and the other is the actual greatest athletes which is much less subjective as far as actual ultimate physical capability.
For my top actual greatest athletes I could start here with my top 25:
Men
Rank Score Athlete Date Venue Ref
1 9,126 Kevin Mayer (FRA) September 15–16, 2018 Talence [24]
2 9,045 Ashton Eaton (USA) August 28–29, 2015 Beijing
3 9,026 Roman Šebrle (CZE) May 26–27, 2001 Götzis
4 8,994 Tomáš Dvořák (CZE) July 3–4, 1999 Prague
5 8,891 Dan O'Brien (USA) September 4–5, 1992 Talence
6 8,847 Daley Thompson (GBR) August 8–9, 1984 Los Angeles
7 8,832 Jürgen Hingsen (FRG) June 8–9, 1984 Mannheim
Bryan Clay (USA) June 29–30, 2008 Eugene
9 8,815 Erki Nool (EST) August 6–7, 2001 Edmonton
10 8,795 Damian Warner (CAN) May 26–27, 2018 Götzis [25]
11 8,792 Uwe Freimuth (GDR) July 20–21, 1984 Potsdam
12 8,790 Trey Hardee (USA) August 19–20, 2009 Berlin
13 8,784 Tom Pappas (USA) June 21–22, 2003 Palo Alto
14 8,762 Siegfried Wentz (FRG) June 4–5, 1983 Filderstadt-Bernhausen
15 8,735 Eduard Hämäläinen (BLR) May 28–29, 1994 Götzis
16 8,727 Dave Johnson (USA) April 23–24, 1992 Azusa
17 8,725 Dmitriy Karpov (KAZ) August 23–24, 2004 Athens
18 8,709 Aleksandr Apaychev (URS) June 2–3, 1984 Neubrandenburg
19 8,706 Frank Busemann (GER) July 31 – August 1, 1996 Atlanta
20 8,698 Grigoriy Degtyaryev (URS) June 21–22, 1984 Kiev
21 8,694 Chris Huffins (USA) June 19–20, 1998 New Orleans
22 8,691 Niklas Kaul (GER) October 2–3, 2019 Doha [26]
23 8,680 Torsten Voss (GDR) September 3–4, 1987 Rome
24 8,670 Michael Schrader (GER) August 10–11, 2013 Moscow
25 8,667 Guido Kratschmer (FRG) June 13–14, 1980 Filderstadt-Bernhausen