Here's a fun one in Brussels (well not all that fun, pretty tough to navigate!)

https://www.google.com/maps/@50.8359...,18z/data=!1e3

I tried to do one in Sun City, AZ where they have a couple of concentric circle street layouts but the streets are a little too far apart for real fun - you only get the inner arcs

https://www.google.com/maps/@33.6182...,18z/data=!1e3