OpenRC's the only init system I've actually liked. It's one of the things I really miss from when I used Gentoo, and I don't know why more distros didn't adopt it years ago.
You should check out SMF, if you have a couple of hours to play with Solaris.. it handles things that systemd does (socket activation, process management/watching etc;) but in an orthogonal way that makes sense.
I like openrc, I also like runit (for different reasons) but SMF is the gold standard for me and I recommend more people check it out. Even if it has XML elements :(
OpenRC was definitely my favorite init system before systemd existed. Definitely beat out the defaults of distributions who were using the debian/redhat style sysvinit.