If we compare the original Nintendo and Sony franchises
this gen, I think both would be about on the same level.
Of course, as Nintendo has such a longer history making videogame hardware and software, their line-up if viewed throughout history is (or should be, if quantity really does matter in this
) larger.
Here's what come to my mind, if there are more, or if some are wrong please feel free to add or correct.
This gen, Nintendo:
Pikmin
This gen, Sony:
EyeToy (London Studio)
WRC Rally (Evolution Studios) (Is this Sony studio?)
Getaway (London?) (Succesfull... hmmm..?)
Sing Star (London Studio)
Throughout history, Nintendo:
Mario
Zelda
Donkey Kong
Pokemon
F-Zero
Pikmin
Metroid
Animal Crossing
Wave Race
Throughout history, Sony:
Gran Turismo (Polyphony)
Wipeout (Studio Liverpool)
WRC Rally (Evolution Studios) ?
Getaway (London Studio)
F1 Series (Liverpool Studios)
EyeToy (London Studio)
SingStar (London Studio)
Ape Escape (SCEI)
Twisted Metal (Incognito)
Edit: I delibrately left out Jak, Ratchet & Clank, ICO and Sly Raccoon out from Sony's list, as they would only cause too much argument whether they are Sony studios or not (and because I really don't know, though I'd guess Naughty Dog is essentially a Sony studio), or whether they are "franchises" as such (ICO)