Must install apps/tools

Whatever you need to be productive.

➕ 💯

This is the correct answer. 👆

Not one of the other replies (so far) addresses the question to the OP: "What do you want to accomplish with the machine?".

🤷‍♂️ 🤦‍♀️
- But OP is asking us. Presumably for the benefit of the community.
  
  If you believe your answer would be more valuable to also include what you are trying to achieve, by all means, include that.
Brilliant.

This is like somebody asking you what you want for breakfast, and you say "Food".
- I'm not sure if you're being sarcastic, observant, or something else. There have been many a meal where I was asked what I wanted to eat and it's rare that I go beyond the words "surprise me", knowing full well that the person asking would eat the same as I was offered, making the "surprise", less of a risk and more of an adventure.
  
  In this case, OP asked a completely unanswerable question to which there was absolutely no reasonable answer, since we know nothing about the person, their interests, their experience, the hardware they have access to, or anything remotely resembling a needs analysis.
  
  So, even my answer, generic and random as it might appear, was based on how I use a computer, namely, to be productive. I've been using them for over 40 years, mostly like that, with some sojourns into art and personal expression, not nearly worthy of public scrutiny, but not specifically "productive" as such.
  
  So .. what were you attempting to say?

Fortune. Cowsay.

People replying - how about telling us why you consider your answer a must-install tool?

Helpful answer: vlc, libreoffice, gimp, inkscape, zathura, obs-studio

Real answer: gnome, run-or-raise, foot, fish, tmux, fzf, silver-searcher, neovim, neomutt, vifm

Curious why you would need Gimp and Inkscape? Wouldn't one of them be enough? Is one of them better suited for certain tasks?
- They serve two different purposes - Gimp for image editing, Inkscape for vector graphics.

For me personally I install kitty terminal and integrate it with fish asap. Then I waste a bunch of time customizing it to my liking. My preferred text editor is Kate regardless of what DE I'm using and I usually get bleachbit for basic cleanup.

Fish and Kate hell yeah 🤜 🤛
Hello Beryl. Could you help me with bleachbit settings (tick boxes)? Once when I used bleachbit, it changed back the icons of packages like Zen Browser that I have changed through Menu Edit. It also removed start up applications from the setting. I'm on Arch KDEplasma. So, I was wondering, which check box should I leave empty to preserve my icon customizations and startup apps?

I'm going to try to mention things I haven't seen already written, though I may repeat some of the more important ones to me.

(In no particular order)

Terminal:

Kitty (Main Terminal)
Fish (Terminal Prompt)
Neovim (Code/Text editing)
Zoxide (a directory changer; once you go to a directory, you can type z and a partial name to go back to it)
Atuin (a command history lister, can get a key and bring over commands from other systems)
Midnight Commander (CLI file manager)
Btop (CLI system monitor)
Palette (I do a lot of theming in different configs as well as HTML/CSS, so its nice to have something to quick convert hex to RGB).

GUI:

Timeshift (backup/restore)
Eddie (for AirVPN)
novelWriter (my FAVORITE writing tool for my books)
Floorp (Firefox fork browser)
Conky Manager 2 (desktop monitoring widgets)
Rofi (keyboard launcher)
firewalld (tried this out recently, good firewall)
Flameshot (ALWAYS; its my favorite screenshot tool)
MPV (I still get VLC, but opt for MPV most of the time for videos/streaming)
Speedcrunch (A+ calculator)
Steam
Lutris
Protonup-QT (to inject GE Proton into Steam/Lutris)
Stremio (a great little streaming tool)

I would like to add that I do use Arch, but I'm fairly sure 99% of these packages, if not all of them, are available for most other distros.

For CLI lovers: Check out Terminal Trove

Edit: I did see that someone mentioned no explanations on the apps, so I tried to put a little blurb on each.

There's a lot of letters here, but nobody is explaining what they mean. How do I know what I need? I'm not gonna install everything, or look up every single program to see.

Potentially unpopular opinion: a bunch of rust replacements for the common terminal utilities: eza, bat, dust, fd, helix. Also fish and nushell, yt-dlp, and some of my favorite programming languages.

All of these alternatives and you missed the best one ripgrep (rg). The other ones in my opinion are nice to have. Recursive multi-threaded grep that respects gitignore files is a must for me.
- I have it installed on a few of my machines but don't really find it that useful. But then again that's specific to my needs and usecases.
I also do this. There are some utilities I'd like to see included directly into most *nix distributions, like fd.

I use bin to manage the utilities, and can setup a new install by just bringing he binary and config. It works great--I highly recommend it.
- Never heard of bin but this is cool as hell thanks for shouting it out!
I just discovered bat and eza, which were already installed, along with fd though I haven't played with that one yet. I've really liked the first two at least

Timeshift is number 1

Also it's recommended to not reinstall a bunch of stuff and just install the app when you needed it that's the power of Linux. Unless you just want to learn the software then disregard

LocalSend for quick local network file sharing from my phone that just werks. I prefer it over kde connect because the latter uses lots of random ports that kinda bloat my firewall whitelist. I know there is an alternative called warpinator, but I don't see a reason to change my preferences for now.

Xournalpp - a fantastic tool for journalling (on X/twitter) your peeing habits.

Tmux - a nice tool for telephoning elon musk
- Wezterm - a utility for tracking the term limits of Wez Anderson style presidencies

CopyQ is an advanced clipboard manager. Gimp is great but Pinta is easy for quick, minor image adjustments. System Monitor is an applet that displays system information by double clicking on a taskbar icon. If you use VPNs, the IP Indicator applet shows the country of your public IP or customized icon when matching ISP is found.

Kate
Yakuake
Brave, Vivaldi, Chromium
LibreOffice (I use Calc a lot)
Kate
Ocular
DoH-client
htop
ncdu
Windscribe
virt-manager

... and more I can't remember right now, because it's too early in the morning.

EDIT:

nano
mc (midnight commander)

mpv
pdftk
yt-dlp

I'm a former Windows user, so I install activate-linux for similar experience.

sl and KDE plasma

Probably would run into these things needed in this order:

The text editor kakoune
Add uBlock Origin to Firefox
KeepassXC
tmux

Then nodejs if it's a laptop, or Steam if it's a desktop.

System :

zram (who says you can't just install more RAM 😄 )

Terminal :

kitty (terminal emulator)
fastfetch (must take screenshots to show off every new Linux install, it's in the EULA)
zsh (thought I'd like to try nushell one of these days) with zsh-syntax-highlighting, zsh-completiions and zsh-suggestions
GNU Stow (to manage symlinks, I store my dotfiles in a repo witch contains home, etc and usr folders, and I use GNU Stow to symlink them respectively to /home/username, /etc and /usr, that way all my config is in the same place so I can back it up easily and have version control)
rsync (to sync backup folders)
btop (system monitoring)
clamav (antivirus)
brightnessctl (for screen brightness control, but I should probably use brillo instead https://www.youtube.com/watch?v=pGOaSS8nEQA)
yt-dpl (for downloading videos from YouTube/TikTok/wherever else)
ani-cli (for watching anime from the terminal, obviously a must-have for any ~~Arch~~ Mint user)
figlet (to write text from fonts made of ASCII art)
cpipes, asciiquarium, cbonsai, matrix for when I get bored in meetings
hollywood and rust-stakeholer if I ever need to pretend I'm doing something productive
lots of TUI apps from https://github.com/rothgar/awesome-tuis

General GUI apps :

Sway (tiling WM) though I'd really like to try niri (instead of several workspace it has a single one of infinite length that you can scroll through)
rofi and rofi-calc (app launcher that can also do a lot other stuff if you want like file browser, ssh menu, calculator, emoji selector, it's very light and superfast), also rofi-emoji (emoji selector)
VSCode (code editor)
KeepassXC (password manager)
lutris, steam, protontricks, ProtonGE (gaming)
FontManager
Ventoy (for making USBs with multiple ISO on them)
LibreOffice

Internet :

Waterfox + LibreWolf (web browsers) with the following extensions : uBlock, Consent-O-matic, DownThemAll, KeepasXC-Browser, Copy PlainText, Copy Link Text, EPUB Reader, Markdown Viewer Web Ext, Sponsor Block, Return YouTube Dislike, YouTube Anti Translate, CanvasBlocker, Font Fingerprint Defender, WebGL Fingerprint Defender (I had to give up on User-Agent Switcher because it causes me to be blocked on too many websites)
qBittorrent (BitTorrent client)
FileZilla (FTP client)

Media :

XVview (image viewer)
ksnip (GUI screen capture)
Gimp (image editor)
Inkscape (vector image editor)
MPC and VLC (audio/video players)
Libation (to liberate Audible audiobooks from your account)
cheese (camera)

I'm on Arch so the package names might be a bit different

GIMP (with photogimp patch)
Steam
Librewolf (I could also opt for a chromium based browser)
Tor Browser (to browse onion links/throwaway browser)
Heroic Games Launcher
Prism Launcher
latest Java lts (either from adoptium or openjdk i dont care about flashy new features)
Libreoffice Still (similar to the second reason above and onlyoffice in appimage due to Libreoffice weird handling with ppsx files and powerpoints)
QEMU/KVM with virt manager
Gnome evolution (if it's gtk desktop I could opt for other email clients)
Proton-GE
WINE
Ghostty(Kinda sucks it's based on libadwaita and gnome forces this theme on you no matter your desktop)
Fish/ZSH(fish not having posix compatibility is kinda annoying)
MPV (I could still use vlc but I prefer mpv because it can stream youtube links)
ytp-dl(I can opt for a gui for convenience sake)
BTOP
Fastfetch

You can try bass to run bash scripts in fish
- Cool find but I will probably stick with ZSH

Shell: Fish
Resource monitoring: Btop
Browser: Librewolf
Text editor: Vim (unless you do heavy programming then neovim)
Basic tools: git and wget
Themeing: GTK customizer
Terminal: Foot

vim, htop , iotop, screen, nslookup.

Qalculate

guix and/or nix

Both are functional package managers and manage dependency trees better than flatpak IMO (also the package description languages mean you can manipulate the package definitions at install time much easier)

If you can't find a package in guix/nix then it behooves you to use flatpak

Zram

only neofetch

I recommend fastfetch nowadays since neofetch is no longer maintained

kitty, nvim, fish, zed, mpv, btop, borg. Weird how all the gone ones have short names. Depending on the system, I would add tlp as well.

At the very least:

Yazi Eza Kitty Fish Fastfetch Feh Trash-cli Micro Spotify-player Nmcli Polybar Rofi (fuzzel for wayland) Librewolf

Firefox with uBlock Origin and Consent-O-Matic. Oh, wait, you said "Linux Mint", not "every single OS, for work, personal, and mobile use".

Darktable. A replacement for adobe lightroom.

I've actually found RawTherapee to be slightly faster for what I'm doing (slight edits to my amateur photography)

vim and docker