I last played when shadowlands came out, I was severely disappointed in the expansion, so i quit in the first month.
Now I’m back for DF and going to give wow another chance.
So I would like to know what addons you think are must have, and honorable mentions.
Immersion imo, I don’t really enjoy the basic quest text but that’s not specific in any way to DF.
Must Haves:
Deadly Boss Mods
Weak Auras (or TellMeWhen)
Tidy Plates
Healbot (if you’re a healer)
Great to haves:
Handy Notes
Tom Tom
All the Things
Details! Damage Meter (or Recount)
Nice to haves:
Immersion
RareScanner
GTFO
Alcoholic (if you’re going to have a few alts)
Altoholic* lol
Excellent list IMO. For newer players, I might argue GTFO is must have, but overall excellent!
I use the base UI and I downloaded a bag addon ArkInventory to let me better sort my inventory.
For the auction house I use Auctionator, lets me easily add my items for sale and gives me notifications if Im about to make a mistake like putting stuff up for less than vendor or a 10k item for 1k.
I use big wigs for my dungeon notifications.
Handy notes with the dragonflight addon- (you download handy notes and then also download the pieces you want, like dragonflight, legion, etc… Its veyr useful for finding stuff like hidden chests, pets, etc… The draognflight one has the locations of the dragonriding glyphs.
I use Hekili priority helper to help me with dps rotations, im not good at remembering them so I use that. It tells me what buttons to hit next to keep up with a good rotation for my dps specs.
Leatrix plus I have downloaded to autoaccept part invites, auto sell gray items at vendor and auto repair at vendors that can. Its very usefull with a few other things like auto quest accept and some other options you can turn on and off as you want.
I have tomtom for coordinates, makes it easier to tell people where something is 
I also use weakauras, people make some amazing uis to help keep track of buffs, skills, etc…
I plan to do m+'s so Ill download raider io at some point. I also have pawn and simulationcraft to help me figure out my gear better. I use this in conjunction with the raidbots website to keep my pawn updated with what stats I need based on what my gear is currently giving me.
Nice list that Argenta made; many addons mentioned were in the guides and YouTube vids I have looked at. Others to mention are Atlas, Titan Panel, and ReputationBars.
As for me, I have been trying to figure out which addons to drop and delete. So far, I have found out that Bagnon, Bartender, and Dominos are of no use in the new xpac. I have ChocolateBar and Carbonite, and those are not working, so I will have to find substitutes (if anyone has suggestions, I welcome them).
Also, it would be nice to have a quest addon for DF. I miss having the quest levels displayed, and the authors of Questie said in their Discord channel that they have no plans to include DF in their updates.
I am thinking that it would be helpful to have a list of addons that do not work with Dragonflight and their closest substitutes, if any. So far, my search on the Internet has not found one.