When Google Maps was good, I could use it to do various tasks that are not related to finding the closes shopping mall or restaurant, for example I could see where the equator is, measure distances (not in the "directions to..." way), and so on...
Now seemly all map-related software decided to gear themselves toward car-based navigation and forgot other uses.
Stuff I tried:
Google Maps itself: Interface was drastically changed, and they disabled the links that would allow you to force a certain interface, and it INSISTS in defaulting to me in the "lite" mode, that can't even measure distances, has horrible interface even for navigation, and is slow.
Bing: Has no meridians, equators, tropics, etc... so if you want to use the map for example with a compass and other basic navigation tools, you are out of luck.
Mapquest: Seemly decided to use Google terrible interface and slowness, AND imitate bing in not having meridians and other basic navigation lines.
Openstreetmap: Maybe has useful features, but keep nagging non-stop for me to register, I could find any way to enable navigation lines, neither how to measure distances.
Not needed for the basic request, but I would also appreciate if someone pointed out some free online map that had some more advanced features, like basic elevation data, biomes, or whatever thing someone would want to know unrelated to human commerce.