Having read the title of the thread, I voted for Other without realising it was multiple choice. So in order from most to least played:
Other - Runequest, most played FRPG this year yet again
Other - Qin: Warring States, and I'm pretty angry the Art of War isn't out yet
D&D 2e, retreading old ground
Other - Legends of Anglerre, because one of my players wanted to GM it
Other - Pendragon, still the best
D&D 4e, PbP only
Other - Anima: Beyond Fantasy, or at least we created characters for it.
BD&D, because a twenty-seven year campaign doesn't stop just because the last player involved now lives in New Zealand
Other - Runequest, most played FRPG this year yet again
Other - Qin: Warring States, and I'm pretty angry the Art of War isn't out yet
D&D 2e, retreading old ground
Other - Legends of Anglerre, because one of my players wanted to GM it
Other - Pendragon, still the best
D&D 4e, PbP only
Other - Anima: Beyond Fantasy, or at least we created characters for it.
BD&D, because a twenty-seven year campaign doesn't stop just because the last player involved now lives in New Zealand