I have a world called Riverside
up at my site. This is a sprawling, large city world that is largely one part urban, one part suburban, but with a few smaller themed districts (like lower income and rural). It's called Riverside because there are a series of beautiful parks along a river that divides the suburban area from the city area.
Below are screenshots. These don't even come close to capturing all the things you can see and do there!
For more information and download links, go here: http://www.thesimsdepot.com/sims-3/downloads/worlds/riverside/