Hajime no Ippo
Time for Ippo to get it's own thread.
For the uninitiated, Hajime no Ippo is a long running Sports Manga centered on the young lad pictured above. His name is Makunochi Ippo and he aims to be the very best like no one ever was. At least as a featherweight. The story starts from Ippo's first exposure all the way until the present day, where Ippo is competing on a world stage.
Now I expect this thread to not have the most attention since despite my saying Ippo is a great manga, most wouldn't read it. At time of writing it has 300+ more chapters than One Piece. It's been going on since the 80's. It's in it for the long haul and frankly if One Piece finished before it I would not be surprised.
Ippo is a very fun manga, with lots of funny humor, great action(I can still recall fights from over a thousand chapters ago for point of reference), and a lot of heart felt moments in there. Has it's flaws but for what it is worth I enjoy it more than any of the Big Three.
So if it looks interesting and the length doesn't put you off then Ippo is worth a look.