Project Visa (projectvisa.com) is a good website for those hard to get visas and countries.
Saudi started a tourist visa program within the last 2 years.
Libya, Chad, Niger and Central African Republic are all on my bucket list. The Libyan embassy in the USA states "We currently do not issue tourist visas.". The others are so war-torn and unstable that even I won't go there at this time. And I have been to some unstable places....