Rating system explained:

5 = The best. The flawless. The timeless. The... You get the idea. Every moment of these albums is enjoyable and I wouldn't change anything.
4.5 = These albums aren't as flawless as the albums above but they are still really good. The flaws can be overlooked and I will listen to these on regular basis.
4 = Solid albums, about half of the songs are top tier, the rest are not. Or 3/4 of the songs are top-tier and the rest suck. These don't get as much playtime as the albums above but I still listen to them every now and then.
3.5 = A step down but still has more good than bad.
3 = Gets less spins than the albums above. I don't mind if someone else is listening to these when I'm around.
2.5 = Funny score. Usually score for movie soundtracks or old (60s-80s) "best of" albums. When it comes to "normal" albums, this is the "hit or miss" tier. They might have some of the best tracks out there but most of the songs are somewhere from "seriously?" to "meh". These albums get a spin when I'm thinking something along the lines "What should I listen to... haven't heard this in a while."
2 = Lower tier funny score. As above but more "seriously? - meh".
1.5 = There are worse albums. Right?
1 = I've heard a lot better but not much worse.
0.5 = The worst. If I could choose between silence and any of these albums, I'd choose silence. Atrocious albums. However, even these albums might have that one good song that ends up into my mp3 player.

NOTE: My ratings are based purely and solely for the music and how much I like the music. I am NOT disputing an album's legendary status just because I gave it a low score. An album might be legendary and extremely important but that doesn't mean I have to enjoy or worship it as the "best thing in the history of music".

Additionally, if you don't agree with my ratings, good for you, you have your own taste, I have mine. Just don't give me shit because I didn't love your favorite album as much as you do.