EC Suite can process in all but a dozen or so countries world wide, and they're places you wouldn't get much internet traffic from anyways, i.e. North Korea.
For truly worldwide credit card acceptances, even from high-risk countries, 2CO has perhaps been the best option. Processors like WorldPay also are excellent in handling worldwide cc acceptances. It all depends where you are expecting to see most traffic from. High-risk countries are the problem and that is where 2CO and others excel (as far as anti-fraud measures, etc.) are concerned.