Based on my past and current experiences with system administration, I just wanted to list some useful and very basic tools I have liked or make use on a daily basis to ease my life and be more efficient:
1. mRemoteNG - a go-to tool in which I configure all of my servers which can be accessible with just a mouse-click
2. Keypass - a primordial password management tool which helps to never forget or remember a password
3. Greenshot - very powerful screenshot tool useful for documenting
4. Notepad++ - copy-paste / coding languages / jotting down random stuffs
5. Microsoft OneNote - essential for a good task planning and all data entered are automatically saved
These are some of my basic and current favorites, to be surely updated throughout time.
I would want to know which one are your favorites and the new trends going on ;)