Slam Dunk manga definitely. And of course Captain Tsubasa, though all I've got of that is three or four chapters from a group that's recently started to scanlate it. I'm sure it's got to be available somehow, though.

Touch never struck me as a sports series, though it definitely involves sports. But I've not watched beyond the first arc of the anime and I think the sports aspect really ramps up after that. And it's certainly a classic and highly influential. I would also highly recommend H2, a baseball manga by the same mangaka.

Hajime no Ippo is a boxing series which is interesting in that it's not a school series, but otherwise is classic shounen sports. I've watched the anime, which I love, but haven't delved into the manga yet because there's so much of it, I don't know how I'd ever catch up. It started ages ago -- maybe more than ten years -- and is still ongoing. I think it would definitely count as classic.

Eyeshield 21 is excellent, if strange, and has all the hallmarks of the genre. Manga over anime, definitely.

I follow some series that aren't super amazing, but are fun. Aoki Densetsu Shoot is a soccer anime that really is, at least as far as I've watched, bog standard shounen sports. All the neccessary elements, just the characters aren't that interesting.

I could pretty easily lay out the elements necessary to build a standard shounen sports series. Which, actually, is kind of what happened with the lacrosse. *g*