Just finished Eyeshield 21.. what now?

All I can say is wow.

I was recommended this series by a friend a few years ago but dismissed it due to the fact it was about american football and I don't really have any interest in the sport. So after giving the first chapter I managed to complete the whole series in about 3 days, and it's now an all time favourite manga series.

My question is though, there HAS to be a series similar to this. A nice mixture of comedy, shounen and Hiruma (Kekeke~), can anyone point me in its direction?