There's always good old trusty Advanced Skeleton, MEL through-and-through. :)
And then there's also Anzovin's work.
I've been at the artist-end of many Advanced Skeleton-based rigs and though it's from the 90s, the rigs themselves have in my experience been surprisingly unsurprising; in terms of bugs and odd behavior. The performance has always been great as well (i.e. 30+ fps), which is more than I can say for most auto-riggers I've been in contact with.
As I Googled, I also found that since 2017, Maya can do auto-rigging out-of-the-box :O