Here's my original answer again:
Pitchpull,
Your question probably deserves is own thread but...
As it stands, an 'Airline Transport Pilot's Licence' will require an IR at the least. Some (ie JAA) will also require some multi-crew time.
However, it would appear that there are moves afoot to introduce a JAA ATPL(VFR). This would be similar to the old CAA ATPL. paco has more details about this if you want them.
So in answer to your question, 'Where in the world is it easiest & fastest', I would say the USA. The FAA IR will be the quickest (and cheapest) to attain in terms of flight time and ground school requirements.