I've been discovering some new and awesome software recently. Here's my grab bag of awesome software that I've found in the past year or so.
This is the big one that will make you way more productive. It's easy to set up, then you don't need to worry about it until you think of something that could be improved about your terminal experience. Then you google that, and discover how easy zsh is to configure. If you use zsh, you'll probably also want oh-my-zsh.
Tmux is a replacement for GNU screen. You should be using it. It takes a while to get used to, but once you do, it's awesome.
Axel is a download accelerator. It finds the fastest mirror, and downloads the file using 4 concurrent connections to make it go faster.
ZNC is an irc bouncer. It runs on a server and connects to different irc networks so that you will always be online. It also has some cool features like a module to authenticate with NickServ and such.
Tiny Tiny RSS is a self hosted RSS reader. You install in in your web server folder, launch the daemon, and it does everything google reader could, but better and more.
Xonotic is a cross-platform FPS video game. It gives me faith that gaming on linux isn't doomed to fail for ever and ever by being as good (if not better that) it's commercial counterparts.
I hope that you fond at least some new software on here that you like.