I only use Research Timer (or whatever it's called) that shows me the time remaining for research in all 3 crafts, spam filter (which apparently is useless) and damage report addon.

Posted this in another thread, but here's what I use:

Sous Chef (which allows you to tell which recipes you've learned, even on alt characters.. and tells you which tier ingredients are from, plus whether you have any recipes that use them)
Research Assistant (marks gear with colors so you know which gear has traits you haven't learned yet, which is a duplicate to something else in your inventory, and which has intricate or ornate traits)
AI Research Grid (allows you to pull up a grid of what traits you have/haven't researched so you don't have to be at a crafting bench to see)
FTC (I use it just for the buffs, but it also displays numbers for health/mana, and scrolling combat text)
Guild Store Search (allows you to type in what you're searching for, and then searches your guild stores for it)
Achievement Tracker (self explanatory)

Sky shards addon because alt tabbing to look at maps to figure out where any skyshards are that I missed was becoming annoying and I would rather just stay in the game.

SpamFilter addon but it doesn't seem to work anymore...I still see gold sellers spamming in chat, I guess I need to configure stuff in the settings? I haven't looked into it...

And last is SlightlyImprovedExperienceBar, it allows me to keep my XP bar to always show and shows the number text and percentage.

Don't really care much for other addons but if there was a chat bubble addon where anybody that said something in /say would have a bubble above their head then I would have that as well.

The LibAntiSpam one is updated daily and is working very well.

http://www.esoui.com/downloads/info211-X4DLibAntiSpam.html

Aside from that I also use Sous chef and guild store search

Just crafting xp messages
http://www.esoui.com/downloads/info113-CraftXPMsg.html

dragon loot since i auto loot
http://www.esoui.com/downloads/info18-DragonLoot-SimpleLootAddon.html

craft research timer to see how long I have left on current research
http://www.esoui.com/downloads/info81-CraftResearchTimer.html

T's combat stats to have a combat log as a chat tab(i dont like scrolling floating numbers)
http://www.esoui.com/downloads/info283-TsCombatStats.html

MoreTargetInformation v2
BagSpaceIndicator v1
LootDrop (modified)

Currently running these addons:
- Alchemist (shows possible potion combinations to discover new traits on a herb, should probably just remove it now that my alch char has it all covered)
- Bank Stuffer (moves partially filled stacks from my inventory to bank IF there are already partially filled stacks of the same component there already)
- BatmanStoreFilter (Guild store enhancement, no IDEA why the game does not offer this function by default)
- Borrower and lender (Are you tired of the bank lady telling you that she is not trusted as a former thief or whatever, over and over again? this is for you then!)
- Combat Log Statistics (Combat log windows, shows xp gains, damage done etc, standard MMO stuff)
- Dragon Loot (Shows items you and your party autoloot, decide yourself if you want a seperate loot window, or in chat)
- Foundry Tactical Combat (Better HUD, scrolling combat text, a must have for me!)
- Greymind Quick Slot Bar (Better quickslot menu)
- Guild Store Search (search items by name in guild store, again no idea why this is not there by default, such a stupid oversight by the devs)
- Inventory Grid view (Tired of scrolling up and down through your 100+ inventory slots? Hell yes!)
- Inventory Item borders (shows coloured border around items, showing their rarity at a glance)
- LoreBooks (shows undiscovered lore books on map)
- Rainbow Reticle (name on mouseover target shows on cursor, coloured friend or foe)
- Research Assistant (shows an icon next to items, when not in grid view mode that is, if an items trait has been researched by you or not)
- Simple Combat Alerts
- SkyShards
- Softcapinfo
- Sous Chef
- SpamFilter (not very good, I think...might try another, or just turn off zone chat if in lower level zones)
- Wykkyds framework, and outfitter - great mod! must have!
- ZrMM (Modified version of ZR minimap, now also works in Cyrodil)

Really great that we have all these mods, fixing the horribly minimalistic (IMO of course, I know some like it for a weird reason) UI. I love you modders!