@masterpeice:
was it more popular than kuroko?
Slam Dunk is the most popular sport manga ever! So obviously it was more popular than Kuroko is now. Haikyuu!! right now is surpassing the popularity of Kuroko.
For Manga it had a 1st print of 2.5 Million copies. That at the time was a record, of any manga not just sport. Only One Piece surpassed that. Well I believe that right now Attack on Titan also surpassed it.
Kuroko no Basket no basket right now has around 1/4 of the copies in print of Slam Dunk, but just 1 less volume. Normally is a good thing for a Series to be able to sell 1/3 more after its ending. But Kuroko no Basket to reach Slam Dunk will have to sell 3 times more.
For anime Slam Dunk had a TV ranking average of 15.3% and the best ranking of 21.4%. Kuroko no Basket isn't even in the Top 10 right now that ends normally in 4%. Is true that right now TV rankings decreased compared with that time, but certainly didn't decreased less than 11.3%.
–- Update From New Post Merge ---
@Robby:
Yeah, FotNS is up there. Just check the sales list and that should give you an idea.
http://en.wikipedia.org/wiki/List_of_best-selling_manga#At_least_100_million_copies
Basically everything in the 100 million+ club is 20 years old at least (except OP and Naruto… and those are 17 and 15 respectively... and are in the exclusive 200 million+ club along with Dragonball and Golgo 13... though Golgo has been running for 45 years and 170 volumes)
I think Bleach and Fullmetal Alchemist are the only series that have come out post 2000 that have higher than 60 million sales, though Attack on Titan will join that rank pretty easily if it doesn't end in the next year or two. (And if Nana would ever come out of hiatus...) And like I said, Assasin Classroom looks to be on track for that as long as it runs a few more years. (Curious to see what happens now that it has an anime.)
Hunter X Hunter and Berserk would both be significantly higher if they came out more frequently.
Death Note might be higher if it had been more than 12 volumes. Bakuman, which debuted in 2008 has sold about 15 million with 20 volumes so it'll be in the low end club eventually.
Forgetting about Haikyuu!! are we? XP
Both Assassination Classroom and Haikyuu!! have right now 12 Million copies in print. With AC with 12 volumes and Haikyuu!! 14. In individual sales Haikyuu!! last volume reached 810k copies sold before getting out of Oricon.
Also you shouldn't count Dragon Ball and Naruto in the 200 Million, nor One Piece in 345 Million. They are both data from worldwide and not Japan, so it doesn't really compare with the rest of the titles.
From the time One Piece reported 345 Million copies worldwide and now, it already was reported that in Japan it got 20 Million more copies in print.
Note: Also Black Jack is wrong! It is just 45 Million copies in print.