Dutch Desire isn't really a contender here. His win rates are inflated due to mostly playing weaker players, and he's not really part of the competitive strategic scene since he's shifted to diplomacy.
I'm guessing the 3 names AI is thinking of are: - Deadman (lots of accolades, also the mentor to a lot of today's great players) - master of desaster (trolled his way to #1 on the 1 v 1 Ladder) - Timinator (first/only player to have 100% on achievements)
I think people have also made cases for: - Rufus - Pardon - professor dead piggy - AI - szewenigen - Gui - Gnuffone - HHH - Buns157 - The Impaller
(with varying degrees of success)
My guess is that Deadman is most likely to be consensus pick.
The cases for the oldies (except maybe piggy) are all now very weak. Gnuffone's achievements are undermined drastically by his cheating, and the field faced by these players isn't as strong as the MDL top 5 today. But someone always chimes in to make a case for these players, outlining how they could still be competitive today.
For me, AI's short list (assuming Rufus, Timi, Deadman) seems spot-on with Pardon, Buns, mod, and AI right on the outside. There's surprisingly few real contenders for consensus GOAT; I thought it would be a very debatable thing, but it almost seems like Deadman is just the unambiguous #1.