I've written quite a few (published) articles about wine over the years. I won't bore you with loads of information about grapes, regions, vintages, etc but I'll just give you a summary brief summary of my own opinions:
The best red wines in the world still come from France. I should make it clear, however, that I'm referring to clarets that cost at least �30 per bottle (for a 'half-decent' vintage wine) but with the really good stuff starting at around �50 per bottle.
If you're looking for the best red wines around �3 to �4, then your safest bet has to be something from South America.
Taking the budget up to �5 or �6, there's a wide range to choose from but, if you asked me to select on the basis of 'country of origin' alone, I'd be looking at wines from Italy or Spain.
It's when you take the price up to around �8 to �12 per bottle that you start to find some really great Australian reds. (Below that price, the only really good Ozzy wines are whites). Whether the Australian wines in this price range are 'the best', however, is a matter of personal taste. (A few USA producers have interesting reds in this price range. Personally, though, I think that I'd stick with Spain or Italy for the best wines at this price).
Chris