These are my ranked expansions, the ones in each category are in no particular order. I´ve combined lore, gameplay and a pinch of nostalgia.
Write your own ranked list in the comments
Wrath of the lich king
Mists of Pandaland (close to best)
Warlords of dreanor
Burning crusade
Cataclysm
Legion
Battle for azeroth
Dragonflight (only because it introduced dragonriding, otherwise bad)
Shadowlands
BEST to WORST:
Many seem to vote Legion high, dunno why though.
Probably because they think its good?
No sh#t, but what made it good according to them.
Order Halls FTW.
Order halls was boring imo, I pick garrison over order halls anyday.
Legion had great story, dungeons, raids and world content that wasnt completely irrelevant doing even for high geared players. The artifact system and legendaries split people, but i personally liked it.
90% of the content in legion made sense doing for everyone, compared to DF were 90% of the content is redundant and a a waste of development time, hence why its been labelled “do once and forget”- content, by many people.
Shadowlands could have been an interesting expansion, however they executed it badly and they ruined the lore.
Mega ultima cool 
Warlords of dreanor (miss my garrison :))
Best
Burning crusade
Awesome
Shadowlands
Battle for azeroth
Good
Wrath of the lich king
Mediocre
Mists of Pandaland
Legion
Bad
Dragonflight
Cataclysm
You dont know why people rank Legion high but then hit us with this…
Anyway for me best to worst:
MoP
Legion
Wotlk
TBC
DF
BFA
WoD
Cata
SL
I’m curious why someone would think WoD is good , when it was so bad that they cut a whole patch out of it , just to make it end sooner and start work on legion . WoD could have been good , but it was a time when leadership changed and the expansion was obviously reworked and scrapped during the expansions itself .
That’s my list :
Mists of Pandaland
Wrath of the lich king
Burning crusade
Legion
Cataclysm
Battle for Azeroth
Warlords of Dreanor
Dragonflight (If it was rated for Story only it would be as bad as shadowlands )
Shadowlands
Panda
Legion
Wotlk
Burning Crusade
Dragonflight
BFA
Shadowlands
Cata
– Vanilla and Wod just played 2 months so cannot say.
The only 2 exp i dont like are SL and Cata. The only good thing with cata are worgen. SL has some interesting things but i HATED the environment (ZM the only one to be saved)
The fact that people rank very differently, just shows how different we are and how hard it is to satisfy all of us in one expansion.
However we seem to be equal about ranking Legion and Pandaland high up 
My list would probably be.
Legion
Wotlk
MOP
BFA
TBC
DF
Cata
SL
WoD
MoP
Legion
TBC
BFA
WOTLK
DF
SL
CATA
WOD
Best: Legion
Awesome: Cata, WoD
Good: Pandaria, Bfa, Dragonflight
Mediocre: TBC, WotLK
Bad: Shadowlands
Legion for me was the best in terms of story, raids, dungeons, mogs and I loved class hall questlines.
Cata is close second because I loved the revamp, QoL changes and the game became less of a drag for me. I can replay it ad nauseum.
WoD was a great expansion for levelling and I adored my garrison, also one of the most beautiful zones I have ever seen.
I liked Pandaria but I wasn’t keen on the ending and the horrific amount of dailies.
BfA is nice to do every now and then, I enjoyed the end as well but not so much the war campaign. The mogs were meh.
Dragonflight story is ok, it’s a nice break from all the rubbish in the world but unsure I will replay it much. Some nice new systems and QoL changes but see more ad a stepping stone to better WoW.
TBC and WotLK are iconically classic but the lack of QoL and amount of grind puts them at the bottom for me. I rarely replay them. WotLK however does have one of the best stories.
Shadowlands… weird story, zones that gave me migraines, horrible end game, the delay on flying, the maw… I got bored the first day after I reached max level and it was a difficult levelling experience for me in the beginning.
Worst: Legion.
AP system ruined it. They also screwed enhancement over.
Best: mop for elemental shaman, wod for enhancement.
Wotlk for holy priest, before serenity, before chakras and so on.
For paladin: the times where they weren’t plate rogues using combo po… sorry, holy power. I absolutely hate holy power, if I wanted to play with combo points I would play a rogue or feral druid, not paladin.
Best:
WOTLK
Awesome:
Legion, MOP
Mediocre:
Cata, DF, BC
Bad:
SL, WOD
Worst:
BFA
This is not negotiable, this is how it was, is and allways will be.
Df
Legion
Shadowlands
Bfa
Mop
Wrath
Cata
Wod
(Cant rank others havent played them other then classic)