94-96, I don't think anyone was close to him. 97 yea you could say Biggie or Prodigy were better. 98-99 he was amazing but the final product we got for I Am/Nastradamus was questionable. But even then a lot of people had heard the leaks and understood it wasn't a matter of losing talent. Just picking the wrong tracks for the album. In short you aren't gonna find anyone who thinks Nas wasn't a top tier rapper - or the best - at some point during that period. 2001-2002...nothing needs to be said. KONY.
Once you get past that period it becomes more cloudy and you see divergence between casual fans, rap fans, and stans. There are dope songs on all the projects he dropped from 2004-2008 but you aren't going to find casual fans or unbiased rap fans saying he was "the best" then. And those albums don't move the needle in GOAT conversations at all. You can walk into a barbershop full of rap nikkas and none of them are going to list those albums. It's gonna be Illmatic, IWW, I Am, Stillmatic, and Life Is Good, depending on age. Same way the Hov dynamic would be Reasonable Doubt, Vol 1, Vol 2, Blueprint, Black Album. and American Gangster, depending on age.