You've already done a top 5 list for beginner distros on a couple occasions, so maybe you could do a video on intermediate and advanced distros as well. I'm sure you've done enough distro hopping over the years to make some suggestions. Of course, even advanced users can make good use of beginner distros, but for people who really want a serious edge, I'd be curious to know what you recommend.
Some potential candidates:
P.S. Sorry about posting multiple suggestions in a short period. I will stop for a while so the thread doesn't get flooded.