I use an absolute shed-load of addons – the majority of these are either to improve the UI or to save me looking stuff up on the internet every 5 minutes.
I use Minion to download, browse and manage my ESO addons, Nexus Mod Manager can also be used of course, as can Curse. I’ve split the addons I use into categories to make it more readable.
Crafting (including Auction House)
Discovery
Combat and UI
.
