All mods which are on the Steam Workshop which are required to join my server.
My server is an immersive survival themed server something akin to oldschool dayz mod on arma 2, to join search for "Apocalypse" or "Chernarus 2035" and join, this collection is every mod you need to join, its good fun check it out!

The only non workshop mod is Exile, to download exile you must download the rar file from their website, and unrar it using winrar or another archiver, once done move the @exile mod folder into the root of your Arma 3 directory, located by default download at;
C:\Program Files (x86)\Steam\steamapps\common\Arma 3
Then on the vanilla launcher in the Mods tab you can select a "local mod" and navigate to the @exile folder you just pasted into arma, select it and load it to the arma launcher. Then you just load all of the mods for the server and launch the game.

Exile
http://www.exilemod.com/downloads/