I recently switched to OSX and have started using iTerm which seems to be suiting all my needs. For Ubuntu I was using Terminator. I like being able to split my window into various terminals so as to code, read build information, and read logging information concurrently.
I use zsh as my shell. It has really nice themes and autocompletion.
Vim is my choice of text editor purely for its ubiquity. I write a code on remote machines so vim is really handy. I use a bunch of plugins to help me. I've started(recently) using Vundle to manage my vim packages.
I use syntastic with JSHint for my linting needs.
I've used both gulp and grunt(comparing them would require another post) for building my code. I'll be writing more on this. I've spent quite a while figuring out the best build tools that work for me while working with React. But that would take up a whole post.