One thing that does make a difference is whether you are looking for a place to settle down in permanently (a new home) or somewhere pleasant to work for a few years.
I assume that if you care about political stability beyond the "will stuff happen that affects me" level (vik seems to, both in the original question and his reply to my earlier comment), then you must be settling permanently. Immigration rules can be very different for the two scenarios (visas to work or run a business, vs citizenship).
The other thing is the low cost of living criterion. Are you planning to get work in the country you go to? Then what you are concerned about is the ratio of cost of living to earnings. In this case you want a developed country.
If you are working on the web location may not affect your earnings in which case you probably want a developing country. You will probably get a lower cost of living if you are willing to compromise on how good the infrastructure is.
Also, cost of living depends on what you spend your money on. Here in Sri Lanka housing is cheap but cars are expensive. In the UK cars are reasonable, but housing is expensive, and so is going out. I believe that in Singapore eating out is cheap (it was last time I went there, compared to most developed countries) but both cars (still the case?) and housing are expensive. If you have (or plan to have) children you need to consider the cost of education.
My current choice compromises on infrastructure (broadband good enough to list to audio while working is enough - big downloads like video and linux ISOs can be done while I am not working, and I can live with the odd bumpy road) and political stability (it does not affect me personally, so why should I let it put me off?).
Viks list of criteria is going to require compromising on something!