Looking for sets with lots of printed parts or other special parts to use as components for my city
All of the decorations in the LEGO Juniors (now called LEGO 4+) sets are printed, and they tend to have a lot of nice decorations. Decorated parts in the LEGO Ideas sets are also almost always printed, but double check this because at least some of the sets also have stickers. 

There is not one set which is going to be full of printed parts, and sets with printed parts tend to be more expensive when it comes to price per piece. If you are looking for a large quantity of specific printed elements, you are better off to just order exactly what you want from BrickLink, the online LEGO marketplace.