I agree with Soggyboxers, Douala is a real nice place to be based in. Good hotels of international standards (Novotel, Meridian & Ibis), excellent restaurants and great night life in especially in the Akwa suburb.
The only annoying part is the police which can get upsetting to the extremes: last month I got stopped at three roadblocks over a half-mile in the middle of the night and I had to pay at each one
!!! Crime is also a bit bigger there than it is in Libreville, Cotonou or other French-speaking capitals -- nothing in comparison to Lagos or Joburg though.
Have fun!