My choice is definitely Vim which I have been using for about a year now. The honeymoon phase is over but I still really love Vim. It’s awesome if you are willing to take the time to learn it. My second choice would be Kate, which I discovered thanks to the excellent recomendations of the forum members. I never liked nano, but that’s just me.
Eventually, I would like to learn about emacs but emacs seems to be even more of a philosophical quest than Vim. Just setting up GNU emacs with evil mode to do basic text editing would require a time committment I’m not willing to undertake right now.