I've found the more I've played, the better RPing has become. So notable campaigns for me were Casse (where the first generation were wiped out [except 1 great general] and it was up to a rather weak second generation to consolidate the British Isles), Baktria (all those disloyal FMs a - trying to marry into my family and b - causing plenty of problems) and, finally, Pontus (some great mountain-men FMs who stayed fighting the Seleukids in the mountains as the more "royal-minded" FMs were trying to conquer Asia Minor and the Crimea).

But for me, it has always been about tracking FMs from early on - I find it hard to start RP a character if I've not kept a track of his movements, etc. So newer campaigns worked better.