About a year ago I started a big Ranma 1/2 kick. There's a ton of episodes, so I'm still not finished. It's pretty nice though. I'll finish work and have some time to myself once in a while, and I'll put on an episode or 2. I'm in no rush to finish, and that makes it comfy. It's a fun show, but the main plot quickly evaporates and it becomes a rival of the week type scenario with a lot of comedy mixed in. There's always some new master of a bizarre exotic martial art, like rythmic gymnastics martial arts, or martial ice skating, or martial tea ceremony, or martial french cuisine. They inevitably challenge Ranma to a fight using their form of martial arts, and he needs to learn the basics of it, and combine that with his own mastery of the Anything-Goes style to defeat them. And the curse that was inflicted on him causing him to transform into a girl whenever he's splashed with cold water will frequently complicate things. I'd recommend it, but only if you're looking for something highly episodic. There's not a lot of progress towards the overarching plot, and there is quite a bit of filler. However, if you're tired of the modern nonsense and looking for more of a classic anime with fun fights, fun characters, open admiration of masculinity, and perverts going on panty raids, then you'll probably enjoy it.
I've never watched Fist of the North Star, only seen clips. It's on my list of things to get to though. It definitely looks like it's fun and /fit/-oriented.