Best cash game player ever is probably Chip Reese; considering he ran the game and got it (big game at Bellagio) from 600/1200 all the way to 4k/8k at the peak of the boom and was supposedly consistently profitable through the whole time playing highest stakes from the mid 70s to late 2000s. Obviously Doyle has to be in the team picture as well. Ike Haxton, Patrick, Chan, Johnny Moss, etc. etc. all deserve nods. Jungleman, if he can maintain this level for 2-3 more yrs also deserves consideration. Longevity is key to me.
Best tournament player is probably Ivey or Negreanu. I'd give it to Ivey bc of his success at the series which he usually is playing along with late night cash games, which is crazy. Seidel, Chan.....all deserve consideration.
Best overall is almost certainly Ivey bc he is so damn good in all the games and in both tournament/Cash game formats. Johnny Chan is sort of somebody who has retired so people forget, but apparently annihilated high stakes cash games for awhile and everyone knows about his ME prowess.
Doyle.....ya.....has to be in the picture.
Honorable mentions you might not of thought about for overall best players of all time:
Scott Seiver(sicko in everything...online, live, ME, High Rollers, cash, HU)
Ike Haxton (Probably the best
online poker player of his generation/WPT #2/more donkament success than people recall)
Michael Mizrachi (plays a lot of high stakes live cash in Fl. and does very well for himself)
Bobby Baldwin (retired early, but many people think he was the player of the 70s and he only left for an even more lucrative career in hospitality)