Linux

I personally use my own script over du itself. It also lists the biggest files and has same options -n and -d as well. :D https://github.com/thingsiplay/biggest It will count hardlinks only once, therefore list only the first found file of a hardlink; even across other directories.

Edit: BTW directory sizes are also output in an instant: biggest /usr/bin and biggest -n 10 /usr/bin/* to list the 10 biggest files in that directory.