Forget micro-nations and egotistical maniacs; I happen to have a passport from a country with population of 250,000 in a relatively large land area. It has its own infrastructure, generates most of its own power and has an economy. It also has a passport that is so useless that it does not rank on Passport Index - World's passports ranked by power.
Behold the Turkish Republic of Northern Cyprus passport:
Established in 1983, it is only recognized by Turkey. Stats:
# of countries that you can get in without Visa: ONE. Take that South Sudan with your 28 visa free countries!
# of countries you can get in with Visa: 6
The grey territories won't take you in no matter what you do.
Thankfully, Turkish Cypriots are also qualified to have the Cyprus passport which is the officially recognized country governing the island of Cyprus. Oh and that passport makes you a EU citizen so that balances things out a bit.
If you are curious about how all this happened, please read this rather informative Wikipedia entry and marvel at the power of humanity to mess things up: Cyprus dispute