LogFAQs > #961582847

Now that I'm at home, I can actually do a count:

Super Mario (14) - 1, 2, Lost Levels, 3, World, World 2, 64, Sunshine, Galaxy, Galaxy 2, Odyssey, 3D Land, 3D World, Land 2
Final Fantasy (14) - I, IV, V, VI, VII, VIIR, VIII, IX, X, X-2, XII, XIII, XIII-2, XV, Tactics
Mega Man (18) - MM1-10, MMX1-6, MMZ1, Soccer
Street Fighter (16) - SF1, SF2, SF2: CE, SF2T, SSF2, SSFT2, SFA1, SFA2, SFA3, SFIII, SFIIITS, SFIV, SSFIV, USFIV, SFV, SFEX

Honorable mention to Sonic with 15

That's if we're just limiting it to mainline Mario games. If we include all the sports games and RPGs, it wins in a runaway with 43 (and maybe more if there's stuff I've missed).