One Punch Man is technically a "reboot" though remake is a better term, but not the manga to the anime, which is actually very accurate to each other. The series is a reboot of the original web comic series though, with a more skilled artist redrawing the story to make it a bit palpatable for general audiences.

I've never been big on reboots because it's hard to recapture what often made the original great. If I wanted a reboot of something, I would probably choose something I felt was awful but the core idea was pretty sound. Dexter comes to mind. Biomega is another manga series that starts off great and then just took a left field into weirdsville before just ending unceremoniously with half the interesting characters MIA for half the series.

As far as spin-offs go, I would have loved a Daria spin-off about Trent and his band Mystic Spiral (though we're thinking about changing the name) which would have been awesome.