It's a matter of preference really. I personally don't like many of the new school rappers I don't understand it and I think it's pretty much awful for the most part. I did enjoy the Carter albums before the kid turned gay and Lupe I couldn't get on the skateboard and push skate at all.
I will give you my input on rap because I'm a rap purist - or atleast I consider myself one.
You gotta split it up imo: Entertainers and Lyricists
Entertainers: Jay-z, Tupac, Biggie & Puff, Slick Rick, Big Daddy Kane, Master P, G-Unit, Snoop, Dre, Cube, Bone Thugs, Onyx, Naughty by Nature, Digital Underground were(are) great entertainers. Today's day I'm sure Wayne, Kanye could fall into this category.
Lyricists - flow, delivery, content, style (off the top of my head): KRS-One, Big Pun, Big L, Kool G Rap, Ras Kass, Crooked I, Kurupt, Black Thought, Mos Def, Talib, Nas, Cormega, Showbiz & AG, Inspectah Deck, Raekwon, Ghostface, Ill Bill, Immortal Technique, Chino XL, Ju-ICE, Eminem, O.C., Canibus, Sick Jacken, Tash, Outkast. Lupe and maybe early Wayne from your list could fall into this category.
New School Lyricists (off the top of my head): Blu, Slaughterhouse, Brother Ali, Aesop Rock, Crypt the Warchild (Outerspace), Reef the Lost Cauze