This is why Sony is one of the largest first party dev out of the three companies for their own game consoles. These are all Sony owned franchises.

Sony owned franchises:
* Alundra
* Ape Escape
* Arc the Lad
* ATV Offroad Fury
* Battle Arena Toshinden
* Blasto
* Blast Factor
* Buzz!
* Colony Wars
* Dark Cloud
* Destruction Derby
* Downhill Domination
* Dropship
* Eight Days
* Extermination
* EyeToy
* FantaVision
* Field Commander
* Flow
* Formula One
* Ghosthunter
* God of War
* Gran Turismo
* Grind Session
* Heavenly Sword
* Hot Shots Golf
* ICO
* Intelligent Qube
* Jak and Daxter
* Jet Moto
* Jumping Flash
* Kileak: The DNA Imperative
* Killzone
* Kinetica
* Legend of Legaia
* Lemmings
* LocoRoco
* MediEvil
* MLB
* Motor Toon Grand Prix
* MotorStorm
* NBA 'xx (year)
* NBA ShootOut
* NCAA Final Four
* NCAA GameBreaker
* NFL GameDay
* NFL Xtreme
* NHL FaceOff
* Okage: Shadow King
* Omega Boost
* Philosoma
* PoPoLoCrois
* Porsche Challenge
* Primal
* Ratchet & Clank
* Resistance: Fall of Man
* Rogue Galaxy
* Shadow of the Colossus
* SingStar
* Siren
* Sky Odyssey
* Sly Cooper
* SOCOM: U.S. Navy SEALs
* Super Rub-a-dub
* Syphon Filter
* The Getaway
* The Legend of Dragoon
* The Mark of Kri
* Turbo Prop Racing
* Twisted Metal
* Uncharted: Drake's Fortune
* Untold Legends
* War of the Monsters
* Warhawk
* White Knight Story
* Wild Arms
* Wipeout

thats honestly a huge list.

Ever heard of Quality is better than Quantity?

Prime example right here.

I suspect if you wanted to, you could find a similar list for Nintendo as well. However, I'll admit, its a pretty big list =).

Rockstarjerry981 has a good point though, how many of those franchises are worth having?

I can already think of some missing titles off the top of my head:

Heavenly Sword
Battle Arena Toshinden
NBA 'xx (year), MLB 'xx (year), etc.
Untold Legends
Field Commander

I'll go with quality over quantity. Unless, of couse, Nintendo's list is bigger. Then, it is definately: Numbers matter.

Eh, you could spin anything anyway. That is my new motto.

About 90% are worth buying. The rest are basically rentals. Only title out of that list not worth it is rub a dub. 

Well, in your opinion. My must buy's are Ratchet, Jack, Sly, God of War, and, maybe, Uncharted.

About 90% worth buying? Thats and opinion, not a fact.
Actually 90% of those games aren´t even in the radar of most gamers,at least the one´s that aren´t diehard Sony fans.

sony has some great franchises.  its a shame they dont get more sales.

 I figure most of those games are rated pretty high. They might not be looked at and under the radar but they are worth buying and fun. Even KillZone with it's 72% rating is fun to play through at least once.