Hunter x Hunter (148 Episodes) Seems childish for the first few episodes, but everyone I've shown it too and forced them to keep watching it just loved it to the end.
Kuroko no Basuke (75 Episodes - 3 season) - Men playing basket ball, MANLY highschool BASKETBALL!
Gintama - If you've seen enough anime to understand Japanese Popculture, this is a such a fun series
Legend of the Galatic Heroes - A classic, older artstyle, but is highly regarded.
Hajime no Ippo - regarded as one of the best sports anime, boxing, unique artstyle with hypey animation and soundtrack.