NUMBER ONE: Dark Anchors
1. Make Them Feel Like an Event
Dark anchors are currently confined to a small area, and have no impact on the world around them. Change that! make it so that anchors, if left open for too long, begin to impact the world by filling it with Daedra of all types. For example, an anchor left open for 10 minutes will begin to send out scamps and clannfears to various towns and cities, harassing players and killing NPC guards at the edge of town. If left open for 30 minutes, an anchor will begin sending organized squads of scamps, clannfears and dremora to raid and seize towns , preventing quests in the town from being completed until the daedra are repelled in a siege-style endeavor. After 4 hours of being open, a massive army of 200 high level daedra will pour out and begin slaughtering players, low level and high level. At this point, a zone will become absolutely overrun, with the only way for players to access it being a concerted effort to siege and take back various cities and towns. The times that these things occur will be adjusted with the zone's population, of course.
2. Cross Over Into Coldharbour
You should have to cross over into Coldharbour to close an anchor. Once the outside defenses of the gate have been breached, you and everyone else can go into the anchor, entering a wailing prison-type zone, where you must clear a large area and fight a zone boss that requires team work to kill. This boss should be big and powerful, and it should feel like a true manifestation of Molag Bal. Around the boss would be areas of different heights, with the boss moving from large cliffs and shooting balls of flame down to ground level where he smashes players with powerful AoE melee attacks. Once defeated, the anchor closes in a flash of light and the players are scattered to various places around around the zone, with a small buff called "Favor of Arkay" that gives you 1 free revive if you die in a PvE zone within the next 2 hours.
NUMBER TWO: Trading
Trading. Zenimax, you can handle this one of two ways. 1: Add a specific trade channel for each zone where people can put up their WTS and WTB offers. 2: Add local auction houses in each zone. While I do enjoy the personal interaction with other players when trading in the current system, an AH would allow trades to happen more quickly and conveniently, with none of the annoying COT fees or having to meet up and do the trade that way.
NUMBER THREE: UI
Currently, the UI is spread across the screen and gives very little indication when i am approaching low stamina/mana. I think that the Stamina, mana and health bars should be clustered together in a pyramid shape, so that all of them can be seen in a single glance. Also, they should have a number and a percentage of the maximum amount on them. The default should basically look something like this:
NUMBER FOUR: Public Dungeons
Public dungeons really do need to be instanced. Having other players run by with duplicate NPC followers from quests (Even if some are named different and wear different armor, they have identical dialogue) is just plain immersion breaking.

Not to mention that having public dungeons ruins the "dungeon crawling experience" that previous ES titles like Oblivion and Skyrim nailed. Instead of sneaking around, listening to NPC conversations and slitting throats, my method of play is cancelled out by players who charge in shouting battlecrys and swinging their axes.
NUMBER FIVE: Paint Armor
Seriously. Not cool. When everything but the shoulder pads looks two-dimensional, you're doing armor design wrong.
NUMBER SIX: Dungeon Design
The dungeons, even the solo ones, are fairly poorly designed. They are often just a few corridors and rooms with clusters of 2-5 npcs, sitting there with no converation or actions. In skyrim, the NPCs would talk, walk around, eat, sleep, mine, craft, and make random noises. The NPCs in The Elder Scrolls Online sit there, static, waiting for something the happen. Sometimes they have very simple patrol paths. but that's about it.
NUMBER SEVEN: Enemy AI
Let's be honest: the AI is brutal. When a mage uses a freezing spell to hold me in place, he should back up so that i can't hit him. Otherwise, what's the point of the spell? The same thing goes for snares and pretty much any stun. Also, enemy NPCs are oblivious. you can walk within 10 feet of a hostile NPC, and they don't notice you. NPCs should be more aggressive, with larger detection areas and less time between when they see you and when they start their attack.
NUMBER EIGHT: Player Collision
I know, people don't want this because of the potential for griefing. So, here's my solution: give players an item that, when used, allows them to walk through other players for 10 seconds. That way, anyone who tries to surround an NPC or block a door, can't.
NUMBER NINE: World Detail
In skyrim, if you wandered, you would find dozens of dungeons, cabins, overturned merchant caravans, bandit camps, spriggan-filled caves, and other locations that had no quests tied to them. ESO has only a handful of areas like this. Sure, there's the occasional camp with a lore book or one cave in a zone with no quest, but the number of large, non-quest locations is severely reduced. As a matter of fact, you can barely walk for 2 minutes in ESO without finding a quest.