This gen? uhm... not enough good franchises thsi gen, IMO. Gears, Resistance, Uncharted... hopefully Valkyria Chronicles...

Does a franchise have to have more than 1 game in it?... otherwise this will be a difficult list.

Allowing single game entries:

1. Wii series
2. Endless Ocean
3. No More Heroes
4. Zack & Wiki
5. Lost Winds

Ace Attorney
LittleBigPlanet
Valkyrica Chronicles
Assassin's Creed
Uncharted

Mario
GTA
Halo
Final Fantasy
Metroid

no specifc order

Bioshock
No More Heroes
Wii Series
Modern Warfare
My Life as a ...

at Evo03 - read the OP

1. Modern Warfare - I know your saying its Call of Duty which isn't new. But if you look closely the new one is dropping the Call of Duty title and is just called Modern Warfare 2. Plus even if it is Call of Duty its the first one that's modern and not WWII.

2. Resistance - Fantastic game. Many unique weapons and great online play.

3. Uncharted - Amazing graphics and fun gameplay. Cover system is as good as Gears of War's system.

4. Bioshock - Great game. Only played it a couple times.

5. Rock Band - Gave us a better option for music games instead of yearly Guitar Hero's.

Honorable Mentions - Gears of War, Left 4 Dead, Dead Space, Wii Sports, No More Heroes.

no more heroes
pokemon ranger
Pokemon Mystery Dungeon
Lost Odyssey
left 4 dead

only have 3
lost odyssey
mass effect
the witcher

Metroid
Zelda
Advance Wars
Mario (only the proper games, not the spin-offs)
F-Zero

1. Oddworld series

2. GTA series

3. Final Fantasy series 

4. God of War series

6. Dead Space