I've tried most types of manga out there, but Sports manga has always surprised me. I don't play sports. I don't watch sports. I don't even like sports novels really. But I thoroughly enjoy manga with sports in them. I don't seek them out necessarily, but every so often I come across them and can't get enough of them.
Last week as I was working my way through the graphic novel collection looking for torn out pages (that's a whole separate rant), I picked up Prince of Tennis by Takeshi Konomi. This series focuses on Ryoma, 7th grade tennis prodigy, and his teammates of the Seishun Academy's tennis team. With the only exception that most of the students look to be either high school or college students, this series looks at sports in an exciting fashion. Ryoma is a confident player--even though he loses every day to his former tennis pro father. I highly suggest trying these sports series out--even if you don't like sports. They may just surprise you!