Reccomended Map readers

[Earthrider]

Greetings, for a long time I have been using an old map reader that's kind of obscure and that few know of (minutor); however, ever since the last update it fails to show me an updated picture of what the map looks like when I download the file.

My question is, what is a good map reader that is simplistic, easy to use, and can show you an image through the .dat file of the map folder. (also one that doesn't require you to install a bunch of auxiliary programs or link to some other application online).