From OpenSUSE there’s also leap micro. Never used it, but maybe worth looking at.
If you don’t like fedora it might still be worth trying one of the fedora atomics, depending on what you didn’t like. For instance, I could never get used to dnf, but it’s largely irrelevant on an atomic distro anyways.
I would love to see a true atomic Debian-based distro, but I think that’s a long way from maturity.
Edit: opensuse aeon will also be released soon, but at least the comments on this post seem to think that there’s some important things missing from Suse atomic.
Ya know, I never really processed it before, but that’s Frank Herbert making a Greek mythology pun/spoiler: the atreides