Vim, mostly. The customization is remarkably easy, just copy my .vimrc and .vim out to the server. I have a folder containing all of my dot files which I sync between servers, and a simple bash script which creates softlinks to them in my home directory.

However, I don't do remote development as much anymore since I picked up the habit of using Vagrant locally. Now I can edit the files locally (though still with Vim), and debug them on a local VM. Throw in Salt and Ansible for orchestration, and once I get my local VM working, I know my remote end will work as well.