Not quite sure why you have to say you're including Nintendo like it's different or a surprise, however, I feel like my list is similar to most:

Ninty

1. Zelda
2. 3D Mario
3. Fire Emblem

Sony

1. Ratchet and Clank
2a. Spyro
2b. Gran Turismo
3. Uncharted

MS

1. Halo
2. Gears of War
3. Forza

Nintendo: Zelda, Pokemon, Xenoblade.

Sony: God of War, Ratchet and Clank, Jak and Daxter, Uncharted, The Last of US, Resistance, Demon souls, Heavy rain/Beyond, Sly Cooper, InFamous, LBP, Tearaway. Team Ico games.

Microsoft: Gears of War, Halo, Fable, and even DR3 looks awesome, I just haven't played it yet. (Just remembered Dead rising isn't exclusive, forgot I have DR2 for PS3)

I got nothing for Microsoft. Sorry guys.

Sony:
1 - inFamous
2 - em... Puppeteer was cool?
3 - I dunno Tokyo Jungle

Nintendo:
Apparently Zelda becomes an entirely different franchise every time its art style is changed a bit, so I'll have to say
1 (tied) - Zelda with heavily stylized graphics
1 (tied) - Zelda with lightly stylized / nondescript graphics
1 (tied) - Zelda with moderately stylized / anime graphics

God, what a waste of three choices that was.

Microsoft

1. Halo

2. Forza

3. Killer Instinct

Nintendo

1. Legend Of Zelda ( particularly OOT )

2. Donkey Kong Country

3. Super Mario Bros. ( Particularly Mario 3, Mario World and Mario 64 )

Sony

1. God Of War

2. Uncharted

3. Gran Turismo ( Particularly GT3 )

Nintendo
1. Pokemon
2. 3D Mario
3. Zelda

Sony
1. Uncharted
2. Gran Turismo
3. -

Microsoft
1. Forza
2. -
3. -

Not quite sure what to put for Sony, as a lot of franchises have been discontinued, are 3rd party or have had a history of hopping between platforms.

I've generally never been a big fan of 1st party games.

Microsoft
1. Halo
2. -
3. -

Sony
1. LittlBigPlanet
2. Ratchet & Clank
3. -

Nintendo
1. Zelda
2. 3D Mario (Including 3D Land/World)
3. Smash Bros.

Nintendo:

1. Metroid
2. Zelda
3. Mario platformers

Sony

1. The Last of Us
2. Uncharted
3. ?

Microsoft

1. Age of Empires
2. Gears of War
3. Halo

Loved the mentioning. I was gonna put it in number 1, but felt lazy to do it.

Microsoft
1.) Halo
2.) Forza


Sony
1.) Legend Of Dragoon
2.) Killzone ( best online multiplayer I've ever played)
3.) The Last Of Us

Nintendo
1.) Pokemon

I know there is only 1 LOD and TLOU but those are my favs.

From what i've played on Xbox, i like Halo alot but thats it

Playstation

Uncharted/ whatever Naughty Dog makes
Little Big Planet
Resistance
Syphon Filter
The Getaway

Nintendo

Mario (any game)
Donkey Kong
F-Zero
Rare's titles on SNES/ N64