I've written hunt reports on both Cameroon (forest) and most recently, Benin. You could have a look at those (be warned - I'm long winded).
I don't know about CAR - you'd have to be pretty risk tolerant to go there now, if you could find an outfitter to take you. The last person I heard of who hunted there had his hunt cut short when he and his team were shot at by the Lord's Resistance Army. I guess if you survive that, you'd have some bragging rights, but they wouldn't be worth much to me, since after the first mention, I'd be recovering from a frying pan to the head from my long suffering wife). You could add Burkina Faso to your list - I haven't been there, but I think, based on what I've been told by those who have, that my comments on Benin could likely be applied to Burkina Faso as well.
Both Cameroon and Benin are great hunts, but very different, just like the countries. Cameroon is effectively a one-man fiefdom, while Benin is more democratic. I ran into a good deal of corruption in Cameroon, while I saw none in Benin (which is not to say there isn't any, but that given that there is so little to steal in the country, I expect it's at a lower level!). The forest (jungle to us) is hot and humid; Benin is hotter and dry. Cameroon has animals which can only be hunted elsewhere with difficulty - bongo is likely limited to Cameroon and Congo these days, Lord Derby is only really Cameroon and I'm not sure if forest elephant can be hunted elsewhere - while Benin tends to the more common West African species, while being a great destination for western savannah buffalo. Also consider that hunting bongo with pygmies and their dogs is an experience unlike any other in hunting, as is hunting the jungle, where everything wants to bite you, sting you or suck your blood (some all three; give me tsetse flies every time). Cameroon is more expensive than Benin, likely a reflection of those unique species. So both hunts are quite different.
Having said all of that, if I had to pick one place to go back to for a hunt, and I didn't need a particular animal found only in one or the other - so going where I want to rather than where I have to - I would pick Benin. I just had a great time there, and as difficult as I found the heat (I would go earlier in the year next time), I found everything else much more congenial. It's a destination which is not visited by many hunters (I believe about 60 in total last year), so the experience is much more "old Africa" than you might find in Cameroon. There are a very small number of outfitters, so your due diligence will be straightforward, and the odds of having a poor hunt are very limited.
But both are well worth a visit.
