Kabul
I have worked there and lived there on and off for the last ten years. One thing to always bear in mind is that the local Afghani doesn't like outsiders in his country, especially westeners. It pretty much depends on where you will be acommodated in the city. The typical form is to have an apartment block that is heavily guarded, and that is where you will stay for the majority of the time. Your only travel will be from there to work and back, and this will usually be in some form of guarded transport. The transit to and from work is probably the most dangerous - this not as a result of the security situation there, but as a result of the poor roads and the shocking standard (or lack thereof) of the drivers - you should probably expect to have some form of collision every couple of months, so accommodation close to the airport is an advantage.
Cost of living is expensive, unless your company is paying for that. It is a dry country, so don't expect any sundowners. The weather is extreme - very hot during summer and freezing during winter. Flying conditions are dangerous. Together with the weather, ATC is sporadic with very poor comunications, the airspace is crowded with a combination of civil, millitary and unmanned craft. The large majority of pilots do not have English as their first language, so often confusion is the norm. The terrain is out to catch the unwary with MSA's in excess of 20,000ft. The only runway at Kabul with a precission approach (ILS) has a steep approach and due to the terrain you have to establish on the glide from above. Landing with very strong cross winds is normal.
So, in a nutshell, as the previous post said: Er......Dangerous. Good luck anyway, it will sure put hair on your chest.