I have a few interesting ones.

Download a video:

alias yt="yt-dlp -o '%(title)s-%(id)s.%(ext)s' "

Execute the previous command as root:

alias please='sudo $(fc -n -l -1)'

Delete all the Docker things. I do this surprisingly often:

alias docker-nuke="docker system prune --all --volumes --force"

This is a handy one for detecting a hard link

function is-hardlink {
  count=$(stat -c %h -- "${1}")
  if [ "${count}" -gt 1 ]; then
    echo "Yes.  There are ${count} links to this file."
  else
    echo "Nope.  This file is unique."
  fi
}

I run this one pretty much every day. Regardless of the distro I'm using, it Updates All The Things:

function up {
  if [[ $(command -v yay) ]]; then
    yay -Syu --noconfirm
    yay -Yc --noconfirm
  elif [[ $(command -v apt) ]]; then
    sudo apt update
    sudo apt upgrade -y
    sudo apt autoremove -y
  fi
  flatpak update --assumeyes
  flatpak remove --unused --assumeyes
}

I maintain an aliases file in GitLab with all the stuff I have in my environment if anyone is curious.