Linux is a free and open source kernel available to the world to use and modify free of charge. Since it's introduction in 1991 by Linus Torvalds, Linux has been customized and built upon to meet the needs of a variety of complex environments. It runs many of the devices and servers we use every day. The customizations are numerous.
When you delve into the world of Linux, you'll find many people with opinions on what application, Desktop Environment, Distrobution, etc. is best for this or that. You'll also find that it's difficult to keep your goals in sight because of the fog of so many opinions. Just remember that no one can know your environment better than you, and only you should determine what works best for your situation.
If you just don't know...do the research. Don't let other people make the determination for you.
There are many different Kernels, Distributions, Desktop Environments, Window Managers, Terminal Emulators, Text Editors, Database platforms, Web servers, Coding languages, etc. It's all so much to handle at once, so you'll really want to do research for yourself and find what will work for your needs.
What works for me:
I've been working with Linux servers for nearly 20 years. With that said, I've been using Fedora as a desktop OS since 2003 and before that, Mandrake. I've been accustomed to the Gnome desktop environment ever since. A few weeks ago, after many years of being away from Linux desktop, I've taken the plunge once again and found more than a few useful tools. As a desktop system, Manjaro meets and exceeds my needs as an OS. The desktop environment Gnome is useful as well, especially on a tablet (MS Surface Pro 3). However, while doing research, I found that an old friend Xfce desktop environment has come a long way since the last time I used it. I won't go into the reasons why it meets my needs, just know that it's what I consider to be the top solution. So, with Manjaro as a OS and Xfce as a desktop environment I am able to customize my Linux box further by installing pre-packaged software with a few simple keystrokes. Manjaro uses the same package manager as Arch Linux (pacman) which makes installing and removing packages a snap. Testing has never been easier. When it comes to toolkits, mine includes the following: