My thoughts for what they are worth...
Four years ago I was in a position to invest. I gave consideration to Cape Verdi but felt I would have to flip the property as it would soon be saturated and I believed that air travel would eventually become very expensive (and I still do). At that point, who will go to Cape Verdi? If I had bought there, I would have been out again by now.
I would have loved to invest in Vietnam and if I had enough spare cash, I still would. Difficult for foriegn investors but possible and getting easier. Stable, all be it, non-elected government. No religious violence now or likely. Beautiful, friendly, developing fast, it will soon be a tourist destination of choice IMO. One more bomb in Bali and the Australians will be flooding there. I chose against it because of the difficulties, especially from the UK, due to distances to get there regularly enough to keep an eye on the place. If you've not visited Vietnam, it's well worth it.
I actually bought in Cabarete, Dominican Republic. I've seen that Dom Rep has been mentioned in this thread already. Cabarete itself is a boom town and I'm delighted with my purchase as I am looking for a seven to ten year minimum ownership (I'm too lazy to keep selling & buying!) Dom Rep tourism was begining to boom about five years ago and more tourists were going outside of the All Inclusives. The USA had discovered the charmes right on their doorstep and while Canadians & Europeans are still the majority visitors, those tourists from the US will probably pass the Europeans this year. This ties in nicely with my rising fuel concern. In a couple of years time, I might not be visiting Cabarete from Europe but even more Americans will be (I hope!) Cabarete itself is still booming, with lots of building still going on (and selling). I think there is still worthwhile investment to be had there but the big profit would have been a few years ago. Sosua is a town that is much cheaper than Cabarete still. It's the next town along the coast from Cabarete and has a lot of prostitutes and a reputation for attracting "that type" of tourist, which is why I dismissed it when I chose to buy in Dom Rep. That said, I think that if the town gets its act together (and there are signs that it might) it has the potential to move upmarket, in part because Cabarete will be full. The East coast is a different market all together.
I have a property in the UK which I kept being tempted to sell, and then buy in Sosua, especially as the property prices in the UK were obviously going to dip, but I have a good, long term tenant in the property and I decided against putting all (both!) my eggs in one basket. If I had decided to sell, Sosua would have probably been where I would have purchased.
That's my opinion... worth the paper its written on!