Perhaps top 50
Now I know I can mention 20 rappers from the 80s and 20 from the 90s that are better.
90s is easy: Jay, Nas, Raekwon, Ghostface, Gza, Eminem, Dmx, Lil Wayne, Q-tip, Bun-b, Pimp C, Andre 3000, Big Boi, Mos Def, Redman, Notorious, Snoop Dogg, 2pac, Common Sense and that's that and as you can see I didn't even mention all. I can do the same thing for the 80s, even though 1 or 2 might be debatable.
Now the 2000s:
It's honestly just Kanye West that I can say is absolutely better.
Others are debatable like Lupe Fiasco, Talib, Jeezy, Ross, T.I., Fabolous, 50 cent etc. That's all debatable, so he's arguable top 5 or top 10 of the 2000s.
Now we got a few other dudes from the 2000s that might pass him in the near future though like K. Dot, Cole and Drake.
K Dot will obviously pass him, but the other 2 meh perhaps.