off the top of my head:

• vim
• git
• bash
• make
• whatever-compiler-im-using
• curl
• less
• grep

argos-translate for offline machine language translation.

tmux & neovim for editing files and organizing the terminal displays.

asciinema for recording and playing back terminal sessions.

• ranger and mc - both are file managers, and their approach is so different that I choose one of them I need at the moment depending on what do I want to do (mc for traditional file management, ranger for looking around the directory tree and peeking into files)
• htop, tmux - classics
• weechat, profanity - for my IM needs
• ripgrep - for searching through files
• magic-wormhole for file and ssh public key exchange
• mosh for when the network conditions aren’t ideal
• nmap to see if that machine I’ve connected into the network is up and what IP did it get
• bat for quick looking into files
• gdb, with mandatory gdb dashboard
• nvim for serious text and code editing, micro for more casual editing