Popular serif fonts are Times New Roman, Palatino, Georgia, Courier, Bookman and Garamond.
Some popular San Serif fonts are Helvetica, Arial, Calibri, Century Gothic and Verdana.
The print font preferences of three of the copywriting greats:
1) advertising great John Caples liked using Cheltenham Bold for headlines;
2) advertising legend David Ogilvy preferred the Century family, Caslon, Baskerville, and Jenson; and
3) direct marketing guru Gary Halbert used Courier in his sales letters.
So what's yours? (that proven to convert)