Thanks for the replies, I'm not sure any of us have the definite answer.
I'm assuming ipdb is correct, then looking at 2010 releases,
http://www.ipdb.org/search.pl?yr=2010&searchtype=advanced
Then Big Buck Hunter Pro, might just of been called that as it was a single model no premium or LE released.
Avatar, did have a version and a LE, but was the version a "full" version or a pro model, I don't know.
http://www.ipdb.org/search.pl?yr=2011&searchtype=advanced
Looking at 2011, Tron Legacy and Rolling stones get the version and LE treatment. Transformers have a Pro model and then 3 LE's. None have a premium model.
http://www.ipdb.org/search.pl?yr=2012&searchtype=advanced
It's 2012 before you see the Pro, Premium and LE of machines, but even then some are just Pro and LE.
I've got to say it's pretty difficult for a newb like me, who just want to play the game. It's all down to budget at the end of the day, but I think I'd prefer to have full versions so I would think Premium over pro is the way to go, but don't want to pay for collectors (cash) premiums so would shy away from LE's.
I'd guess before 2009 is a full version (2010 depending on what Big Buck Hunter is, but as its the only version, it is the full version), after that, you need to research the machine you like and decide what version to go for.
Tony.