There is no competition to Khabib in the GOAT category.
GSP has 1 fight under USADA.
Jones is a proven roidbag and has 4 clean fights total. Half of those are shitty split decisions which proves that his natural fighting ability is very mediocre.
Anderson is a proven roidbag and has 1 clean win in the UFC. His career fell off a cliff once he could no longer roid starting from 2015 and his performance completely plummeted.
Khabib has 7 fights under USADA and all of his top or simply dangerous opponents except for RDA were beaten by him in the USADA era: Michael Johnson, Barboza, Poirier Gaethje. Never had any problems with roids. The true and undisputed GOAT. Roidbag nut-garglers can go stick more needles in their asses along with their opinions.