ShadowOwl: I guess it doesn't really matter where you start, 1701 is the most modern one available so far and has pretty much anything you might want (campaign, tutorial, endless game, scenarios, gorgeous graphics and music).
I'm pretty sure that 1404 + Venice expansion is going to make it to GOG as well but 2070 is pretty unlikely due to its annoying online components.
Only played 1602, 1404 and 2070 so far, really looking forward to play 1701 now, although 1404 is said to be harder in general and more motivating in later stages of the game.
I've been considering jumping into the Anno games a while. Been keeping an eye on a disc containing 1404 gold + 2070 gold for about $20, but have been steering clear mainly because of the online thing with 2070 and though patches should've removed DRM on 1404, it's never stated if it still has a disc check I'd have to cope with.
But now I'm curious, what is the online component of 2070? As far as I could tell when it released, the online-component was DRM only, but no actual gameplay impact, but maybe this is completely wrong?
Also am I the only one who find it...interesting, that UbiSoft released a city builder which required a persistent online connection to play single player without too much uproar. Then EA released Sim City which seemed to have more actual online features and were cussed into oblivion for it?
Much as I don't like EA I just find it curious how UbiSoft have always pioneered bad DRM practices and EA's taken the blame once they jumped on board after Ubi. I always chalked it up to the fact that UbiSoft often make compelling fun games, and EA often doesn't, but maybe there's another reason?