I got two setups.
the first one is my common dev pc.
nothing special
but I have my 16GB RAM, 8 core i7, ssd laptop which i mainly use for customer visits, and I bought it for concurrency experiments with GO and other languages :D ....
Windows 10 second boot (for gaming) Now for the more interesting stuff
PHPStorm for Elixir, PHP, JS, Zephir, vagrant
tomboy notes for notes
CouchDB
my Servers which i use for dev as well
I hope I did not forget to much :D I am doing a lot of system architecture and DevOps as well as other things :) that's not even the full stack I use based on the projects .... but it's a lot of toys
my killer apps are "strace|grep|mount|df" the rest varies on the program I'm using. I used Aptana, Eclipe, Netbeans, uEdit, notepad++ and a lot of other things even tried Atom.... as I mentioned it depends on what I need and do :)