I definitely am in no position to say who the best ever was since I'm not big into rap and hip hop, but Scarface and the Geto Boys were great as far as I'm concerned. And yeah I'd heard of them before Office Space.
AmeriKKKa's Most Wanted and Death Certificate are both top 10 albums IMO. 2Pac released about 6 albums (including Thug Life) and all of them were great. Biggie is not a top 10 rapper but top 15 and his first album is a classic whereas the double-disc is extremely overrated. (people say All Eyez on Me had filler yet they give Life After Death a pass despite all the forgettable shit on the second disc) And on the topic of filler for All Eyez on Me, only "Whatz Ya Phone #" is skippable IMO. Everything else serves it's purpose including the chilled out tracks like "Check Out Time" (too underrated).
Eminem in his early days was fire and I love SSLP but MMLP has a bit of filler in the second half which prevents the 'classic' sticker on it from me. Nas has always been great but his albums in 1999 were average at best. And I've already addressed Jay-Z.
I personally prefer Scarface to all of them, save for maybe early Cube.
And lastly, Biggie is more overrated than Jay-Z. Two albums, only one is a classic and he gets treated like some kind of hip-hop God.
Okay what? Have you even listened to BIG? I actually wouldn't argue anyone saying BIGGIE is the greatest because a case can be made. Ready to Die is a top 5 ever in hip hop probably, along with Enter the 36 Chambers, Illmatic, Reasonable Doubt and the Chronic off the top of my head.
Rating Eminem, Cube and especially Eazy fucking E ahead of The Notorious BIG shows you have no knowledge on the matter. Eazy-E is one of the most overrated rappers of all time, trully bad. Eminem was great, still nowhere near the best ever. Jay Z is actually a far better rapper than Eminem.
Most people that are into hip hop would tell you that Eminem isn't even top 10 ever, let alone the best ever.