Addons I have found useful and/or invaluable

FTC (Factory tactical Combat)

An addon dealing primarily with combat feedback. It has different aspect that can all be turned on or off independently, making it completely customizable. The primary function is the health magicka and stamina bars grouped together, and giving exacting numbers for the player, and exacting health for foes. It also track buffs and debuffs on the player and buffs and debuffs on the foe. Also adds an experience bar that will be visible any time you are not mounted (the mount’s stamina bar covers the experience bar). It has a build in DPS gauge which will help you compare you stats to other players. A key element it just added is that the group window color codes the roles off your party, making it easy to tell when the healer or tank are down. The color of each role can be chosen by the player.

Destinations

An addon that enhances your map and/or compass. Completely customizable, you can turn on or off what you would like to use. it will add map and or compass pins to your map and/or compass for many different thing, points of interest, fishing holes just to name a couple. Also gives information on fishing holes, as to what fish can be caught and what bait to use. Not always 100% actuate, but still useful.

Skyshards

Simply put, an addon that helps you find skyshards. It adds a pin to your map and/or compass so that you do not have to worry about missing them.

Lorebooks

Simply put an addon to help you find lorebooks. It adds a pin to your map and/or compass so that you don’t have to worry about missing them.

Lootdrop

The addon that makes tracking auto-loot possible. It creates a window that will show the items, experience, and gold that you collect while using auto-loot.

Lost Treasure

An addon that creates pins on you map and/or your compass. No more do you need to even look at a treasure map, so you will have a mark that tells you where the treasure is! Also works on crafting surveys.

Minimap

First and foremost, I do not recommend this for anyone under the recommended requirements for ESO, not for anyone with a slow internet connection; it does cause a bit lag. It creates a minimap that looks like the map you would open in the game, but in a small, movable window.

Public Dungeon Champions

An addon that adds pins to your map and/or compass for bosses in public dungeons. The pins change color when you have killed the champion. Also works on the delves in Cyrodiil.

Research Buddy2

An invaluable addon for any crafter. Creates a window with a collapsible table that tracks the research done, or in progress, with the timer, for all the characters on your account. You can also compare traits against other characters to tell what character can make an item for the other to craft, if you end up wanting more than one crafter (I’m soooo guilty of it)

Advanced Filter

An addon that enhances your ability to sort your inventory. Allows further breakdown of tab, such as armor into light, medium, heavy, shield or jewelry. Also separates crafting materials, making it invaluable to crafters.