may 23, 2002, shawn green went 6 for 6, 4 HR, 19 total bases game is the only one that compares with Ohtani's incredible line, i think.
https://www.baseball-reference.com/boxes/MIL/MIL200205230.shtmlgreen had 19 total bases that game while ohtani had 17. BUT Ohtani also had the two steals, so maybe they are even.
ohtani and green's games both added about 0.7 WAR just for the one game.
i would say that either one can be considered the greatest single-game performance in baseball history.
EDIT: the post above has ohtani had 5 fo 5 in that game. he really was 6 for 6.