I have issues with all Jay-Z's albums.
RD is dope, but pretty derivative of Cuban Linx and Ready To Die (among other albums), and nobody considered it a classic at the time. It's also pretty inauthentic - Jay-Z in a Mafioso costume, after the Fu-Schnickens costume didn't work out.
The Blueprint is dope, but lyrically kinda weak, with a couple flat-out bad songs (Jigga That N-gga, Hola Hovito) that don't fit the rest of the album's sound at all.
The Black Album is dope, but also has some weak songs, like Change Clothes And Go (who the f-ck still plays that?) and Justify My Thug (lol). And while some beats are nuts (99 Problems), some weren't all that. There's a reason why the remixes of this album were so popular.
But I don't think "classic" means "perfect." It just means the album has enough timeless music to hold up as a whole. Every classic album has a weak spot.
So, I guess they're all classic, lol.