Unpopular opinion, but BFA had a real chance to be the best expansion, and I really remember it pretty fondly, it just had a lot of misses on content and it seemed like they quickly became unfocused when it came to fixing it.
To me BFA had all the makings of a fantastic expansion, and flashes of brilliance such as BfD, Bwonsamdi, the Drust, the zones, the Snek people...
There was a lot to love, but then they changed the location to Azshara, and then they changed the location again to nzoth and honestly South seas, azhara, and nzoth should have all been their own expansions.