Favorite .io Game?

Recently, there has been a craze on the internet, for multiplayer browser games with the .io extension.

Spoiler: What is .io?

In case you didn't know, io stands for indian ocean, or british indian ocean territory, so it's like using .au, .eu, .ca, etc.
If for some reason, you want to read up on .io and it's popularity, go here: http://www.name.com/blog/business/2013/10/why-are-startups-turning-to-io/

Anyway, I'm wondering what your favorite .io game is, is it Agar.io? Slither.io? Diep.io? Or some other one that is less known?

My favorite is Agor.io. jk. My actual favorite so far is Cursors.io.
EDIT: I found my new favorite, Vertix.io.

 

Slither.io is pretty good...

 

Did someone vote for all of them? I highly doubt that someone has tried all of these.
Even if they have, they haven't followed directions for the last option.

 

I want to actually play some, but I've never gotten the chance to.
They always get stuck at connecting, and I don't think I can do anything.

 

I found my new favorite, Vertix.io.