I think for a lot of rappers here, no matter what you value strongly or disregard as minor in a rapper's style, you'd have to agree with me. My estimation as Lil Wayne as a very good but non-top 10 rapper is actually not one of those rappers, as long as you break agreement with my argument's premise of who the best rappers are and create your own. For the sake of argument, I will make that counterargument, for which I have no real way to prove wrong, and which I have to just end up by saying that we agree to disagree because our arguments premises are completely different.
You'd have to start by saying that rappers should be judged not completely or even by a majority of their strictly musical aspects, but in their artistic yet non-musical forms of expression as well. That's because while Lil Wayne is good but not great at certain of the strictly musical aspects I've described, he is maybe the most compelling artist of the rap world. He became famous at 17. He's from a non-traditional Mecca of rap, New Orleans, that allows him a signature status he wouldn't have in NY or even LA. He gets the best producers. He's wildly famous, and keeps us intrigued with his antics, like going to jail. He made a rock album. He released a number one hit single where he sung. He has an entire about only chewin' the gine. But mostly, it's the fact that Wayne seems insane.
Because that is the ultimate response to the first strictly musical argument against Wayne that I made: that he isn't trying to be technical at all, but that his aesthetic is an uncontrolled one, like MIA's brutality and assault on your ears. An over zealous person might make this argument for many of the other rappers I leave off the top 10 list, such as Snoop Dogg, but Lil Wayne pulls it off with such a consistency and such an outlandishness that it's more convincing. If Lil Wayne added a tight technique to his rap's approach, he would lose much of what makes Lil Wayne, Lil Wayne.
We can further see this as a self-conscious choice on Wayne's part because he shows absolute brilliance at certain moments that, if he could only replicate them, would place him in the same stratosphere as Jean Grae, Nas, or Eminem. For instance, on "Walk In," he has these lines, where the brackets surround sentences and the capitalized words are rhymed:
[they handle all my pharmaCEUTICS]
[i got it from promethazine to metaMUCIL]
[don't MEAN to SPOOK YOU]
[but this is new orleans so my QUEENS to VOO DOO]
Here, we have it all. The perfect imagery and emotions evoked with a single word: voo-doo. The big amount of rhymes. The long rhymes. The pacing, tight phrasing. This line would be right at home in the work of Jean Grae.
But elsewhere, Lil Wayne makes mistakes that the college white boys I heard at school who only got the confidence to rap when baked out of their mind wouldn't do. Check this line, from "Who Wanna:"
[kid SLICK SLICK]
[i CLICK CLICK BLAST on ya bitch ass]
[squad up shit] [clique'll SMASH on ya bitch ass]
[smash on ya bitch ass]
That exact repetition of a line at the end, with no change in meaning or pun, would get booed as a stutter or stumble at a battle rap fight. And yet there it is, and he does this in a number of places.
Basically, this loose artitry works for Lil Wayne because it fits his artistic persona, where it doesn't for others with a lack of technique, such as Twista. Twista's hard as shit, so why isn't his phrasing just as concrete? But Lil Wayne's a complete weirdo. Saying, "I'm a Martian?" Calling himself a goblin? A whole song about eating pussy? "The nickname Tunechi?" Just like Ludacris, Lil Wayne puts an odd turn on the traditional gangsta persona. Lil Wayne would've fit in any rap era, where it's hard to imagine 808s and Heartbreaks getting play in the 90s, as influential as Kanye's album turned out to be.
But no, Wayne would fit with the chill-out have fun of the late 70s, the completely unique and signature albums of the 80s where each took a different approach, the gangsta rap of the 90s, post 808s And Heartbreak, and up until today.