Something that people don't get (as it's a tricky concept) is that OSM isn't primarily the online mapping you see at openstreetmap.org. Just like Linux or GNU isn't about a single distro or use case, OSM is a community and tools for building a variety of different user facing tools from a shared digital mapping infrastructure.

Also, the best of OSM is in places like Germany where in some areas they're mapping down to the level of individual trees and lampost locations as well as where animals are located within zoos.

http://bestofosm.org/#best-of-de-berlin-zoo

http://bestofosm.org/#best-of-ch-bern

http://bestofosm.org/#best-of-fr-strasbourg