When the developed world sneezes, emerging economies catch a cold. This fear explains why investors are quick to shed their emerging-market holdings when the U.S. and European indexes hit rough waters. But it may be time for a new set of rules for investors to follow.

Many economies outside the United States and Europe are far better managed than in decades past, so they’re no longer one step away from yet another major crisis. Sure, the problems facing Greece are immense, but the relative health of a number of smaller economies is strong and getting stronger. Not only do these countries pose less global risk than they once did, they also offer more stability than before. Rising middle classes that stimulate greater domestic consumption means they are less dependent on the boom and bust of export cycles.

It’s exactly these types of countries that get my attention as an investor.

Crucially, investors need to understand that rapid advances in living standards should set the stage for robust growth in the decades to come, likely far more robust that what we should expect in the United States and Europe. The International Monetary Fund (IMF) says this trend is already underway. In its latest growth projections for 2012 (released in September), the banking institution predicts emerging economies will grow 6.4% in 2012, while developed economies are expected to grow a mere 1.6%. The key conclusion: “The situations of emerging and developing economies vary widely, but after strong growth in recent years and on the horizon, most are in the enviable position of being able to invest in growth and employment and to brace against future global economic volatility.”

Still, many of these emerging markets have taken it on the chin anyway in recent months, as investors have been selling off anything that isn’t nailed to the floor. As a result, you can now have some of the most dynamic and promising economies for discount prices. 

I’ve decided to profile three emerging economies worth a deeper look. Each of these three markets are valued at less than 10 times projected 2012 earnings, as measured by the stocks held in each of their primary indexes. These aren’t the usual suspects (Brazil, Russia, India, China), as I’ve said increasingly that while BRIC is important, investors need to avoid fixating on these countries and pay attention to the NEXT big growth stories around the globe. Let’s take a look…

1. Turkey
As I’ve noted in a past profile, Turkey is possibly the most advantageously-situated country in the world, just steps away from southern Europe, central Asia, Russia and the Middle East. As a result, the country is boosting trade in virtually every direction.

Notably, each of those trading partners appears to be on sound economic footing with rising national income: Neighboring trade partners in the Middle East are awash with petro-dollars now that oil is back up near $100 a barrel; Russia, the world’s second-largest exporter of crude oil (after Saudi Arabia) is also flush; and in Asia, the IMF foresees an incredible 8% domestic product growth in 2012.

Turkey has growing pains, though. The country is running a trade deficit as its fast-rising middle class goes on a shopping spree. This means import growth needs to slow in order to alleviate trade balance concerns. Also, Syria and Egypt are key trading partners, and these countries’ economies are slumping badly right now due to domestic upheaval. But in the long haul, Turkey represents one of the most dynamic growth opportunities in the developing economy space. The exchange-traded fund (ETF) iShares MSCI Turkey Investable Market Index (NYSE: TUR) has slid from $70 in early May to a recent $43, creating a fresh entry point for investors.

2. South Africa
After a string of lost decades, key African economies are starting to make major gains. The continent has always been blessed with a lot of natural resources, but emerging middle classes are helping to establish rising domestic consumption. That’s why the IMF says the countries in Sub-Saharan Africa will see their economies grow a collective 5.8% in 2012 (after growing a solid 5.2% this year).

South Africa still stands as the best way to play the region, because its major firms have a strong regional presence in countries such as Nigeria, Botswana and Ghana. Best of all, the Johannesburg stock market has become more attractively-priced in recent months. The iShares MSCI South Africa Index (NYSE: EZA) has fallen from 20% during the past six months to a recent $59 and remains below levels seen back in 2007.

3. Argentina
While much investor attention has been focused on Brazil and Chile, the Argentinian economy has started to build its own head of steam. This may be the start of a long-term reversal after 110 years of misery: In 1900, Argentina had the fourth-largest economy in the world, thanks to abundant exports of cattle and other goods.

Why the turnaround? A currency devaluation a decade ago has made its exports competitive once again. Gone are the days when Argentinian firms would see customers snatched away by lower-cost rivals in Brazil. A surging Brazilian real now makes Argentina the low-cost player in the region ($1 today buys about $4.26 argentine pesos, compared with $1.85 reals). Its stocks also sport lower prices. The Global X FTSE Argentina 20 ETF (Nasdaq: ARGT), for instance, was launched in March at about $15 and has since fallen below $11. The fund owns a broad basket of Argentina-based firms such as oil giant YPF (NYSE: YPF), e-commerce firm MercadoLibre (Nasdaq: MELI), fast-food operator Arcos Dorados (Nasdaq: ARCO) and mining firm Goldcorp (NYSE: GG).

Take a look at the market performance for the three countries in the past five years…

Risks to Consider:  These markets are only slowly decoupling from developed economy markets, so any steep drop in the United States and Europe will surely have a negative effect on their economies.

Action to Take –> The key to investing in these emerging markets is to focus on the long-term. These bargain-priced ETFs look positioned to deliver superior returns during the long haul and are best bought on periodic dips such as what we’re seeing now.