Social Explorer vs National Atlas Map Maker
For making a map of one's neighborhood, Social Explorer wins. Unlike National Atlas Map Maker (NAMM), Social Explorer (SE) lets one zoom in closely into a neighborhood (showing street names). The best aspects of SE: it lets you create a slideshow of maps, it lets you zoom in closely and creates reports about the area based on census data, and all-in-all, failry easy to use. Some downsides to SE: the find tool isn't very helpful, it doesn't allow you to put in your own layers, and when you pick from the different maps (such as maps by age or marital status) it isn't clear what the changes mean in the map.
As far as interactive maps, NAMM allows one to put many kinds of layers on theirs. It's major downside is that it doesn't allow for a close zoom-in of an area. The best aspect is that it allows for some interesting layers (Superfund sites and bat ranges), though it isn't always clear what the symbols mean for those layers even with the map key function. I came to like NAMM a lot because of the fascinating maps one could create with it. It is far more interactive than SE.
All-in-all, they're both great tools for specific needs. If I need a map of my neighborhood with some data, SE could make it while NAMM couldn't. If I need a map invasive species land cover in the entire lower 48 states, then NAMM would be the one to use.