i just like iphones in general. I'm not aiming for the hottest products, etc., etc,, so i would get 4S. Also because, their accessories should be cheaper since companies are trying to get rid of them and replacce them with new ones for iphone 5 or samsung.
The ipone 5 basically only has a couple differences between the iphone 4s. These are that it has a slightly longer screen, is thinner, lighter, and has 4G capability (fast internet connection). The thing that I've heard about the iphone 5 is that it has not as good a battery as the iphone 4s. The iphone 4s is cheaper ($) and also is heavier which I think is good because it gives it some weight in your hands and you have a less likely chance of it slipping out of your hands. The iphone 4s has 3G which has a slower network connection than the iphone 5. It really depends on what you are going to be using your iphone for. In my opinion I would get the iphone 4s bc its cheaper and has beater battery.
The difference between 4 and 5 is the space. When it comes to electronics it is very obvious that the more money you pay the powerful the performance is. but that's just my perspective as a programmer. Hope this helps. ~John