Here's a ranked listing of Fonts.com Web Fonts' top 100 most used Web fonts for October 2012:

Neue Helvetica

Trade Gothic

Helvetica

Neue Frutiger

Univers

Gill Sans

Avenir Next

Futura

Avenir

Frutiger

DIN Next

ITC Avant Garde Gothic

Linotype Univers

Neo Sans

Trade Gothic Next

PMN Caecilia

Agilita

Arial

New Century Schoolbook

ITC Garamond

Linotype Didot

ITC Franklin Gothic

Monotype News Gothic

Frutiger Next

Century Gothic

Garamond 3

ITC Lubalin Graph

Rockwell

Twentieth Century

Abadi

VAG Rounded

Adelle

Optima

ITC Officina Sans

ITC Century

DIN 1451

News Gothic No.2

Trade Gothic Next Soft Rounded

Bauer Bodoni

Eurostile LT

Soho

ITC Conduit

Neue Helvetica Arabic

Laurentian

Sackers Gothic

Harmonia Sans

Frutiger Serif

Soho Gothic

Biome

Univers Next

Times

ITC Fenice

Museo Sans

Yakout

Neue Helvetica eText

Memo

Eurostile Next

Neue Haas Grotesk

Glypha

Georgia Pro

Calibri

MSung

Futura T

Sassoon Sans

Slate

ITC American Typewriter

Candara

Helvetica World

Clarendon

Albany

Rotis II Sans

Heisei Kaku Gothic

Novecento

Akko

Cachet

ITC Officina Serif

Sabon

Iridium

Monotype Grotesque

Neuzeit Office

News Gothic

Bembo

Monotype Garamond

Plantin

Amasis

ITC Blair

Compacta

ITC Legacy Serif

Aeris

Museo Slab

Basic Commercial

Franklin Gothic

Aachen

Egyptian Slate

Serifa

MHei

Camphor

Bodoni LT

Georgia

Baskerville

Ryan Arruda is the Web Content Strategist at Monotype Imaging. Ryan holds a bachelor's degree in film studies from Clark University, and an MFA in graphic design from RISD.