It just depends what info you desire. I typically use "ls -lh" to quickly find large files to clean up to recover disk space.

I use "du <directory> -h -d 1|sort -h" for this because large files may be nested in directories and ls doesn't display the size of content directories (as far as I know). The output is sorted. Note that the "-d" flag for "du" doesn't work with all versions, but there were similar flags on all systems.

I don't usually have access to a version of "sort" that supports the "-h" flag.