When it comes to default passwords, I would quite like a variation of TP-Link's -- of all people -- practice adopted everywhere.
TP-Link clearly mark the default password on the label with the serial number and so on, you see. Which makes it easy to service stuff for which, naturally, the documentation has long since been lost without asking Google.
Now what I would like is for the password to be a derivative of the serial number -- or MAC address, etc. Whatever is appropriate for the type of gear in question -- so that it cannot easily be guessed by a remote attacker.
Well, a way to clear just the password such as on proper network gear would be best, I guess. But not everything has a readily-accessible serial port, and this does not make sense in every case, anyway.