I will always remember Anno 1404 with great fondness. It was the first game in the series that I got to know and it totally grabbed me. I don't know how many hours it made me burn, but I was very enraptured. I agree with what you mention that to this day it still looks great.

I didn't find the sequels to it too bad either, I know at least 2070 got a bit of hate, but I played it and it wasn't too bad haha. The rest I still haven't tried.