I'm always bothered by the use of non-square fonts to depict square geometry, such as in a roguelike or a similar game such as Dwarf Fortress, so I created two square fonts for the venerable code page 437, in 10x10 and 12x12 sizes with a Roman (serif) style.
I probably should have done a search before starting since I'm not the first to have done so and it was a significant undertaking, but I think mine are largely superior to many other attempts at the same size and depth (one bit color/alpha), although I haven't tested every character - foreigners and engineers may object to my rendering of some non-English characters, with which I'm not familiar - and some people may not like the thicker box-drawing characters. I'm a bit happier with the 10x10 font, but the 12x12 font is easier for my aging eyes to read without leaning forward. They're certainly better than the square font that's packaged with Dwarf Fortress. It's hideous! Many characters are horribly asymmetrical.
Depending on your browser, you may need to right-click my fonts and choose "save as" (or similar) if you want to download them.
Dwarf Fortress's square font (4x)
My 10x10 font
My 12x12 font
If that's a question, use them however you like. :-)