Ascii Art Fonts  for logos in ingame chat and so on (thinking of Armagetron but of course it doesn't have to be for that game).

Iceman's ascii art generator is highly recommended, go there and choose the "Ascii Art" page, the fonts are available there :)

Speed2004  a "speedy" easy to read 4-line font. Shown here using a 5pt monospaced font:

  _______ ________  _________ _________ ________   ________   ________   ________  ___  ___ 
 /  ____/ \_  __  \ \_  ____/ \_  ____/ \_  __  \  \___  \/  /  __  \/  /  __  \/ /  /_/ \/ 
 \___  \  /  _____/ /  ___/_  /  ___/_  /  /_/  / /  ____/  /  /_/  /  /  /_/  /  \___   /  
/______/  \_/       \______/  \______/  \______/  \_____\   \______/   \______/      /__/   

the font is copyrighted but free for all non-commercial use

Slanted Scribble  a slanted and slightly confusing 4-line font (tilt your head a bit to the left and it will become clearer). Shown here using a 5pt monospaced font:

 _  _  _      __  _  _    _  _    __    _           _  _   ___   _  _    _  __  _  __  _      __    
//_/_\ \\  _ /__\// /_\_  \\// _ /__\ _ \\_        //_/_\ /__/_ //  \\_  \\/__\ \\/__\ \\  _ /__\ _ 
\__///  \\// \\/_/  \\\ \  \ \// \\//// /__\_      \__/// \\_// \\   \ \  \_\//  \_\//  \\// \\//// 
   //    \/   \/     \\\/   \_/   \__/  \\/_/         //   \_/   \\   \/    \/     \/    \/   \__/  

the font is copyrighted but free for all non-commercial use