I'd seen a couple clips in the past where he (Hikaru) said Kasparov was the goat but I guess he really was just memeing. This conversation sparks a lot or at least some debate and I'm here for it.
youtu.be/JO40F0b9XnU<Comment deleted by user>
They are pretty clear 1&2 and people would have different opinions. It is hard to compare players from different generations who never played each other in prime. Magnus also benefitted from engines becoming better than people and helping out in analysis , which Kasparov did not really had.
To me it is
Magnus Kasparov - Tier1
Fisher Karpov - Tier2