Here are some addons that I use:
General Use:
FTC: Foundry Tactical Combat - DPS meter
Skyshards: marks all skyshard locations on your map
Public Dungeon Champion: once inside a public group dungeon (not solo delves), all the boss locations will be marked on your map
Lorebooks: Marks all lorebook locations on your map
Group Content:
Papa Crown: Makes the crown over the leader's head bigger so it's easier to see
Raid Notifier: An extremely light version of Deadly Boss Mods (used in WoW) - notifies you of events during trial boss fights
Provisioner's Team Formation: Places small icons on your screen telling you where your teammates are - if the teammate is dead, their icon changes to a skull - somewhat useful for finding your dead teammates to rez
These are the ones I mostly use, but there are many more for many different purposes. I highly recommend you download Minion, which is an interface you can use to download, install, and update addons with. http://minion.mmoui.com/
PS. The names of the addons may not be entirely correct - going from memory here, but if you start typing the name of each into Minion, it should bring it up.
Edit: for buying and selling, there is an addon called MasterMerchant - if you hover over an item in your inventory that can be sold, it will give you an average price that that item has sold for in the past X amount of days, with that info coming from the trade guilds you are in. I personally don't use this because it causes errors for me, but I think there is a way you can keep it from causing errors. Others could tell you more about that.
Hope this thread helps future console to pc transfers if it doesnt get deleted.
@ZOS_GinaBruno @ZOS_JessicaFolsom @ZOS_KaiSchober I will legit pay $ to transfer my ps4 account to pc. I'm sure others would too. but i can see where this would be a backburner project or not possible with sony/microsoft. Black Friday Event* special lol. just saying