You have to be a heavy glue sniffer to a make a single player game into a multiplayer game.
i don't see how multiplayer is the issue here. the issue is the scaled down experience in terms of city size, agent wonks, and of course always online, which is being patched out any day now.
anyway cities xl is a technically competent game, 'cept for the occasional mem. leak, but it's "
soulless" and just isn't a ton of fun. tropico is great, but with politics and some light economy management thrown in. anno 2070 is cool, but a good deal less about cities (compared to cxl) than managing resources.
i dunno why you're limiting this to just 3D tho, as simcity 3000 and simcity 4 are imo the tops of the genre, and cheap at that.
P.S. tony stop being a goddamn moron mods for bl dont count