I'm watching Daiya no Ace right now (trying to catch up before SASO) and I love it so much. Great characters, a large but not impossible to track ensemble cast, baseball, the hottest anime sports coach (imo) EVER. Neither Free nor Kuroba worked for me, though, so hard to say if you'd like Daiya or not.

If you like series about adult characters, Giant Killing is really great, though doesn't have a large fandom. It's about j-league soccer, a club that's not doing well and brings in a new coach who is also a former player on the team. Lots of great relationship issues and tension.