I tried neovim for a while and I went back to vim for that reason: setup once, then forget about it.

I have plugins that haven't been touch for 5 years+ and they are working as intended.

Rock solid.

The program sl, works every time

tree, locate, nvim, flatpak, htop, bmon, etc.

tmux, weechat, helix

Caddy

VLC

vim, awesomewm, mbsync (isync),

As for recent discoveries: dwl — I was surprised on how robust it is, and how well it works.

Bottles.

Without it, I wouldn't be able to run addictive keys on Linux. I paid for the software back when I used Windows and since I'm able to use addictive keys on Linux, haven't bothered trying to find an alternative.

That said, its the only use case I've had with bottles that just works. Other programs ive tried are more hit or miss.

grep

zsh

Debian and basically everything in its repos. Might be somewhat old, but it is really fucking stable

Many have already mentioned tools that I also use and appreciate immensely.
My pick is Steam. I've picked up on gaming in the past 2 years and it's very stable right now. Every game that I have interest in just works, I can install games, including early access or demos without looking at the compatibility or the release date. The download speeds of games are high (imho at least where I'm located, and compared with a PS5). My partner is a heavy gamer and has to yet find a game that doesn't work on her machine.

Nginx.

It runs everything at home and at work.

Emacs

KCalc. Man, it just computes! It can add, subtract, and even multiply. It's never given a wrong answer.

I'm on arch and everything I need just works, no fuss. Webstorm, steam, bitwarden, notesnook, mullvad, anything I need just works really. Of course as with any OS there are things that are pain in the ass but that is everywhere no exceptions.

bash. Konsole. vim (-neo or otherwise up to the point it became AI infested). ssh. steam. git i could go on for quite a while

Based on my experiences running multiple servers and pcs on multiple distros for more than a decade, almost all problems originate between the keyboard and the chair attached to the machine running Linux.

Misconfiguration is usually the culprit.

Oh and important note: I run Arch BTW

I'll give a shoutout to the rEFInd boot manager. If anyone has ever had trouble with Grub, rEFInd continues to work for years across multiple machines. I have never had a problem with it.

So many. So many little utilities that just work. To mention a couple I think no one will mention because they are not sexy: Okular and Ark

mc and vim

nano

Depends what "fuss or bother forever" means. Background tools run without interaction, and therefore aren't bothering. But any application with interaction is basically "fussing". The simpler the programs and its scope, less chance of problems are expected. Also updating with an Arch system BTW can cause an issue, that is not even related directly to the program itself. Oh and I'm known to make simple questions complicated...

As a daily user of Firefox and Thunderbird, they just works. I also use the KDE standard terminal "Konsole" and don't remember having a problem. I do screenshots (maybe not everyday, but often) here and there using KDEs "Spectacle". It works as expected. The simple terminal tool fastfetch to display system information works always. After installing searxng-git, to run the search engine server locally, it basically always works without fuss. I just have to update it from time to time manually, as it updates from Git source directly.

Prosody for me. I set it up over 2 years ago, and the only time I touched it was when updating to the latest Debian stable and enabling some new features in the config files. It's been rock-solid and just worked without complaint.

xterm, xv, mc, tmux, gimp, seamonkey

sl

I set up a couple of pi-zeros to monitor our heating and other stuff, it runs lightpd and have been running for several years uninterrupted.
They are only accessible on the local network, so I don't even bother to run updates :-)

I will second KeealiveD.

Pihole has been robust even the upgrades.

Docker has been perfect for years.

RaspberryPi os has been superb.

all rock solid af

monit, postfix, gearman, dhcpd, bind

Sadly even Linux is a fuss. This is primarily due to full os updates needed every four years plus the changing security landscape. Then there are the hardware issues and replacement every ten years. I guess a partial alternative is a rolling release but then you have the issue of constant change.