I love it how people say "ohh Nas, he's lyrically awesome" perhaps, but there's more to hip hop than lyrics, he has a rough flow and it's amazing because sometimes his songs have absolutely no meaning at all.
Illmatic is good, I get bored of it easily but I can understand why others would like it, I'm not going to argue that. Nas' next release was always going to have to be commerical for him to make a name for himself, but the difference between the way Illmatic was done and IWW was just too big, the whole mafioso idea was garbage, why change something that wasn't broke? Nas did that and he ruined it, what saved the album was the Fugees and Hype Williams, their involvement made it was it is.
Stillmatic, once again, just like HHID was released at a time where if Nas dropped a decent album, it was going to be seen as a great album. First of all the name of the album and then what was going on at the time of the album being released with his feud with Jay Z, I bought Stillmatic and have it somewhere and it is a good album, but it is no where near being great. It was great marketing and timing that made it seem great.
God's Son is my favourite Nas album but he's no Eminem, the way the album distanced itself from previous Nas albums was too big of a difference for it to be considered great, when I say he's no Eminem I mean that Nas talking about his personal life on that album song after song wasn't that appealing. Whatever Nas did, he sold consistently, but his sales for God's Son proved even that Nas fans were getting a bit bored. That and his alliance with Murder Inc. at the time was a joke.
Also, there are heaps of MC's who can match him lyrically (I'm not even going to mention old school rappers), for example AZ. AZ has beaten him down in every single track they've recorded together, from the Firm to Illmatic (Hal will back me up on this). Then of course there is Raekwon who is perhaps the unluckiest rapper of all time, because if OB4CL was released before Illmatic, then he would've been the King of New York, OB4CL is a much better album than Illmatic anyway, even Nas thinks so because IWW was a OB4CL wannabe.
sorry for the Waleed like essay, but it is what it is.