What Mods are beneficial to a returning player?

[Immadude]

I've returned to WoW after hearing great things about Legion. I haven't played since WotLK and boy has this game changed. I've gotten my new Pally to 30 just off the regular WoW UI. It has improved greatly. Do you all recommend other mods that can help with UI, Spell notification, Dungeons, Raids, etc?

[Deleted]

First question, what specc do you want to play? I myself I main Holy Paladin. Weak Aura 2 is like my favorite addon. And of course DBM or Big Wigs. (Whichever you prefer)

You dont really need any tho until you hit lvl 110. ConsLegion really helped me leveling up from 100-110.

[Monzsterr]

Some basics
DBM (deadly boss mods) is very good for helping you with boss mechanics. It yells instruction to kick this, move way from that etc.
Bartender is a good UI mod to put action bars where ever you want them. As a paladin with all our abilities being cooldown based I like to put two rows of bars just under my toon with all the abilities that are inportant to track
Weakauras is very useful for tracking basically anything in the game but at this point we're getting quite complicated and beyond the needs of leveling.
Auctionator helps with selling and buying items on the AH
Skada lets you track your damage done (an other things) to see if your keeping up with others and performing well.
adibags replaces the terrible default bag UI with a nice organized single panel window for your inventory.