Bought my first rap album (on cassette) in 1990 and was buying new music almost every Tuesday. Not to mention dubbing stuff from friends so Hip Hop Music has been part of my life since I was old enough to even appreciate music. and I have a pretty wide variety of stuff I like (East Coast, West Coast, Mid West, Down South, Trap, Gangsta, Pop, Underground, Backpack, Conscious, and so on...)
But what I think people don't think about is the fact that there was a lot of pop garbage rap in the 90's too. and when people act like the 90's was superior, they only recall the stuff they liked from the 90's. I have been guilty of this myself. it really takes time to pass to see what lasts to get an appreciation for a particular era.honestly there was a lot of bullshyt released in the late 90's and early 2000's but people get caught up in the "Retro is better" state of mind and blindly make these declarations. My point is there is great music and bad music from every genre in every generation.
And for the sake of discussion...I'll give my personal rankings of the era's that I have experienced and collected music from. Based on the quality of my favorite albums from each era and their replay value. And for what it's worth...I'm not basing this only on what's played on the radio and what's popular or obscure underground mix tapes from unknown people. But stuff you can get from iTunes or buy on CD from an actual store.
Early 90's
Late 80's
Late 2000's
Early 2010's
Late 90's
Early 2000's
Early 80's
(Early = Years 0-5, Late= Years 6-9)
Also for reference here is a pretty extensive list of reviews of 90's albums. I don't necessarily agree with all of dude's rankings, but it is a pretty extensive and well thought out list. You can go to each year.
http://rateyourmusic.com/list/Jespon/90s_hip_hop__what_is_the_best___under_construction_/