Getting Visas for West Africa is a nightmare. Here's is my guide. 8 countries from 1st hand experience and the rest I have attempted to put all the relevant details all on one post. This post. GPS coordinates of the embassies being the most sought after detail that most blogs leave out!
Getting visas for Central Asia used to be a pain in the ass. Now Kazakhstan and Kyrgyzstan offer the traaveller, visa-free stays and Tajikistan and Uzbekistan are obtainable on-line. But it's still worth a post.