I never finished it, was at like ep 20 before my anime ADD took hold and I was leaping on to another one. What I saw wasn't bad, some of it was funny like the tower of doom I think it was called. You had to take a bag of ice up to the top on a hot summers day and then bring it down before it melted. Not the best I've seen, but by no means the worst. Just realized I should rewatch and keep watching it as I was thinking what anime to watch.
Having done a little research since I was looking for a new shonen series to pick that actually has an end, it seems the anime isn't as good as the manga.
So I've been reading Eyeshield 21, and so far the 200 out of 300ish chapters I've finished have been fairly good. It's still a typical shounen sports manga, but it's genuinely clever and funny. Even some of the omake have been hilarious. It's also devoid of knee-grating groan moments.