I think maybe i'm too old when I say Heyheuhei, TeddyFGB, Blue Precision, The Impaller and Duke!
You did say all time!
Yes, so much!
Although, knowing all of these and having played with or against all of them as well as all other good or great players of the last 5 years, I would say:
Heyheuhei: yes, consistent bulk winning
TeddyFSB: yes, ladder top 10 in every year 2011-2014 and multiple great seasonals, very underrated player
Blue Precision: no, great and really friendly player, but not better than me and I'm not an all-time top 10 player.
The Impaller: maybe, but mainly ladder 1v1 in the olden days. When he returned, he was rusty.
Duke: no, he was good, but not better than The Impaller for example.
It's difficult to compare skill over time though. There are many players who play great for a few weeks or months, but then disappear, are they really top 5 all time in that case? Longetivity should play a role as well.
People like Heyheuhei, TeddyFSB, Szeweningen, Timinator, dead piggy, mod, gui, timon92, Yeon check these boxes for me, but I may be forgetting several others.