I've become fond of using Bahnschrift font, and its parent DIN 1451. I'm not a font expert by any means, although I've read up about these fonts out of curiosity.
But I find them elegant, and very easy to read, which it probably why they were used for road signs in Germany in the 1930's, and on License plates.
The link to Wikipedia is a fun read (if you're into such topics)
DIN 1451
