At a command line, type
This will list each device and usage information.
You might find
more readable, since it gives quantities in Gb or Mb, etc.
Use some combination of the commands and options:
du --max-depth=1 2> /dev/null | sort -n -r | head -n20
to view only the largest few. If you’d like to use it a lot, then bind it to an alias, e.g. in bash by adding to ~/.bashrc
alias largest='du --max-depth=1 2> /dev/null | sort -n -r | head -n20'
du . -h --max-depth=1