There's like four different games to opinionate here, it's changed so much since I started. I started playing back in the TBC days in 2007 a few days before the Zul'Aman patch dropped and it consumed my whole life for years, I used to get up a couple of hours earlier than usual before school to play some WoW before I left, then sometimes I'd OD on sugar to feign a fever to fool my mum's thermometer so that I could stay home and play it. I'm in the camp that thinks Wrath was its prime days by far. Plus during Wrath I joined a guild that felt like a family to me and I've got so many fond memories with those guys.
Then the Dungeon Finder ruined the social aspect of the game, Cataclysm ruined the "world" and "second home" aspects, Mists ruined talents, that beloved guild of mine died sometime here and everyone in it has since stopped playing, Warlords ruined general skill-based gameplay and the rewarding feeling you got from levelling characters, and that near-max level boost has always baffled the fuck out of me and must destroy the experience for new players, and now it's a sad little shadow of what it used to be. Since Warlords the story has been surprisingly strong for WoW and Legion made the gameplay "fun" with its class & spec improvements but those aren't what made WoW the monster success it was back in its day.
And it's not just rose-tinted glasses, I've tried playing on a TBC private server and everything I once loved about the game was there intact and I had the same experience I loved back in the day and it gave me the exact same feeling of wonder it once did. My eyes felt heavy from having it all back again, man. I hope classic WoW will bring back a similar feeling but since I wasn't there for vanilla idk whether it'll be a good substitute for me personally or not.
I based my 10/10 rating on its golden age days, I can't give it anything lower with how great it used to be.