I think PES is a bit unique in this regard and should be given a pass and seen as 'PES' rather than any iteration.
PES 3 was incredible as a gateway game to the series, and in terms of awe, would be the winner for me despite not being the best game; PES 2014 was put down by me because I spent an ungodly amount of hours literally making my own game on it, but again, not necessarily the best outright playing experience. I think of 'PES' as all-encompassing on the PS2: I never think of a particular version of the game, but perhaps that's just me? Similar to my thoughts with ISS on the SNES and N64, actually.
I don't think it's the same as, say, fighters or FPS etc. which tend to have definitive versions in their franchises, because once the PES's get launched, the community, or the user, turn it into something else and it branches from there every time, or it certainly did on the PS2 - who do you know who played any version of it raw and untouched once they realised the possibilities in the edit? I think most hardcore PES users probably spent more, or an equal amount of time, editing it to playing it! even, so it's a really unique title, particularly for a console game, as it's usually PC titles that are a mod heaven/haven, not console games.