GeePS uses google maps and works well. I like it for the traffic feature most of all.
Maps: Modrana. It has routing (only online, but with help of routino it will get offline soon, too). It pronounces routing aloud with espeak. It can use wide range of tiles, map or satellite; it can overlay map and satellite with custom transparency; it can use OpenStreetMaps, and it allows easy correction of any errors in map data you can encounter. It can create GPS logs and points-of-interest. It's highly customisable and quickly evolving.