Not seeing anyone recommend Sublime Text here. It's free for non commercial use and is fucking kickass and doesn't look like it came out of the 80's like NP++
The more I look at modern UIs, which seem to have decided the best way to use the metric crapload of screen space a modern PC has is with gratuitious whitespace, the more I like 1990s UIs.
Sure, totally get you there, but part of what I like about Sublime is that the interface is clean, no buttons everywhere, nothing obtrusive, its just a text editor that packs a punch and has a lot of community built plug-ins to do whatever you may need.
Personally I could never use a text editor that is free and not open source (Aside from built-in editors).
For simpler stuff like config files etc I use Kate which looks nice, has syntax highlighting and is cross platform. For more complicated stuff I like VSCodium. Both are well maintained, and work great.