As far as i Know Eve is the second most popular SUBSCRIPTION game that dosn't have a F2P option.
EDIT
FFXI has more
- - - Updated - - -
Did some searching on Google
http://www.alteredgamer.com/pc-gamin...r-populations/
World of Warcraft – 12,000,000 (2011)
Aion - 3,400,000 (mid 2010)
Runescape – 1,300,000 (2009)
Lineage – 750,000 (2009)
Lineage II – 750,000 (2009)
Dofus – 520,000 (mid 2010)
Final Fantasy XI – 350,000 (mid 2010)
Eve Online – 325,000 (2011)
Lord of the Rings Online – 210,000 (mid 2010)
City of Heroes/Villains - 125,000 (2009)
Age of Conan – 120,000 (mid 2010)
Ultima Online - 100,000 (2009)
Everquest - 100,000 (mid 2010)
Warhammer Online – 80,000 (2010)