I've always been a fan of carefully-pixelled UI fonts, but a little while ago I discovered Warp Sans, the system font from OS/2 Warp. It's not as polished Tahoma or Espy Sans, nor as stylish as Chicago or Charcoal, but it inspired me to try making my own pixelly font.
My initial goal was pure readability, so I decided to use a proportionally large x-height. However, my attempts at 'pure readability' wound up looking exactly like 10pt Arial, so I switched to a more stylish, art-deco approach (E, R, 8 and S are good examples).
The current set of glyphs covers all of Latin1 and a good selection of the Latin Extended A and Latin Extended B sections of the Unicode standard. I didn't draw all those myself; I drew the accents and used a program I wrote to automatically combine them with base characters to produce all the accented characters (if some of the accented characters look wonky, that's why). That's also where the glyphs for Roman numerals and bracketed letters and numbers come from.
Since I designed it to be a user-interface font, I'm naturally using it as my system font. That picture also happens to include small samples of the bold variant I'm working on - mostly just a double-struck version of the Regular, except for the few characters like 'e' and 'y' that need special treatment.
So... what do you think?