Mentour Pilot is one the few aviation YouTubers that I like. He mostly covers air disasters (i.e. similar to Mayday), but from a pilot's perspective that is easy for non pilots to understand.

For trip reports, I'm mildly interested in guys who fly on obscure airlines and/or travel to obscure places, but I've yet to find one that I've enjoyed enough to want to watch more than one or two videos.

There is another thread on this topic from about a year ago which focuses on annoying YouTubers.