Watching for gifts for map lovers these days? Some guys over at reddit do so as well. Besides some interesting links (notebooks, OpenStreetMap clothings or map glasses) there was this side link to a great resource if you are searching for downloadable map material.
Reddit user amillion3 pointed to a side with worldwide coverage of maps in 1:500k scale called tactical pilotage maps.
Tactical Pilotage Maps
Tactical pilotage maps “are designed to provide an intermediate scale translation of cultural and terrain features for pilots/navigators flying at very low altitudes (below 500 feet above ground level), through medium altitudes or low altitude-high speed operations.” (source)
The maps are all stuffed with English labels and provide a colourful view on physio- and anthropological features. You can easily select map sheets using these overview-maps which are click-able:
Yet one have to admit, that the Russian topographic maps are a bit more detailed. But they probably served a different purpose. But compare for yourself:
pilot map of the Ugii Nuur area in Mongolia
Russian version of Ugii Nuur area, Mongolia
The pilotage maps are served by the Perry-Castañeda Library Map Collection. They have a great list of available maps and they are all provided as downloadable jpgs/ images. They have old historic atlases, thematic maps and nearly everything a cartographer would fall in love with. So check out the homepage and maybe support them. Most of their maps are released under public domain.
See some examples here: