I have many.
Shadowlands was one of the Best Expansion. It has the best set of M+ Dungeons, it has the best Art for Maw, it has most badazz transmog and mount like the Hand Mount, Epic Cinematic start when the Sky shattered when Sylvanas broke the Helm of Dominion, striking Raid (I maybe biased as it has Sylvanas who drops Legendary Bow for Hunters and I am a Hunter), awesome Mount Creation… you create Mount in Zereth Mortis.
The Maw was the best Zone ever created in WoW. Perfect Art. It perfectly depicts Hell… as Gloomy, Dark and Unfair. Of course, Carebears hate it. They thought Hell has a place of comfort for Sightseeing.
Shadowlands has the best dungeons… Plaguefall, Necrotic Wake, Theater of Pain and De Other Side are among the best dungeons ever created.
Vanilla and Classic was the best leveling experience especially when you never played WoW before.
Current Retail is the easiest version to play becoz of too many welfare rewards. Many were non-existent before. You dont need to Raid to get Tier Set. You use the Catalyst not just for Tier Set but for converting Garbage Loots into something better. The Weekly Vault gets you easy upgrades and you can tune the RNG into your advantage. Easy Delves and easy M+ to make you Raid ready for Heroic/Mythic. Addition of Catch up welfare loots like Dinar, Horrific Vision, Turbo Boosts, Turbulent Timeways, high ilevel gear from OC Delve (and Siren Isle). Ability to get to ilevel 675+ as Carebear. These are all non-existent from the old WoW. Catchup is okay but when you realize that Carebears can access them too, you started to question the game’s difficulty. Am I playing a Carebear game? RoFL. Maybe I am okay for now.