There are lots of MMOs, personal opinion, that ESO is better than. Pick one based on your play experience and list some of the reasons why. If you quote I'll add it to a list below.
Beats Hands Down
World of Warcraft - added by me
Neverwinter - added by skillastat
The War Z - added by razorwire2
For mine, I'm picking World of Warcraft.
I played this game for many years and loved the sub model and the idea of regular content. The only MMOs I've ever really stuck with for any length of time have been sub.
For me, ESO really fixes all the things I didn't like about WoW, when it started going downhill. WoW turned into a button mashing fest, full of rotations and cookie cutter templates everyone felt they had to follow. That ruined a lot of the gameplay for me. ESO, after trying several builds does start to feel more unique and more fun the more you play (though I wasn't impressed for the first 10 mins or so lol).
The graphics were good at the time, but ESO is in another league. I can compare the Aldmeri region with Nagrand. When I first went to Nagrand I loved just looking at the scenery. ESO has areas like that, which put WoW to shame.
Guilds. It was always a pain trying to keep people together. Being members of multiple guilds at once in ESO fixes all that. Phasing. Changing the world through your actions is cool. ESO does it SO much better. Not being able to see people in some places, who are at different stages.. that's a very small loss for such a gain. Besides I can just pick them up again after.
1 tank 1 healer, rest dps. Old. Boring. Need I say more. Sure you can do that in ESO, but I've had lots of great groups that don't. And they've been far more fluid and far more fun.
Elitism: That's one thing I'm really glad to see the back of. Hopefully won't see it too much in ESO.
Note: Had to cut this short but will have to update later / tomorrow.