music: cmus
video: mpv
volume control: amixer
file manager: n/a (core utils)
terminal emulator: rxvt-unicode
text editor: nvim (or some tiny vi clone for speed)
mail client: n/a
image viewer: feh
torrent client: rutorrent
screenshot: scrot
system monitor: htop, ntop-ng, sensors, nmon, etc
multiplexer: tmux
shell: zsh (bash when i must)