Favorite game franchise

Super Mario

Zero escape

bioshock
uncharted

Final Fantasy
Arkham series
Kings bounty
Might and Magic
Mafia
Deux ex
Diablo
Starcraft
Dragon Age
Breath of Fire
Resident Evil
Broken Sword
Monkey Island
Fallout
Elder Scrolls
Dead Space (no 3)
Tomb Raider

These are franchise i would consider buy the game full price on release if i am happy with what i am getting

Civilization, always make me spend one more turn or 4 more hours

Mercenary.

RESIDENT... wait for it... EVIL!!!

Valve count as one?

Series in order of how much I love them:
Metal Gear
Armored Core
Castlevania
Tales of
Diablo
Command and Conquer
Warcraft
Star Wars (old republics mostly)
Starcraft
Halo
Tomb Raider
Halflife
Killzone
Doom
Duke Nukem
Wolfenstien
Zelda
Golden Sun
Advance Wars
Borderlands
Resident Evil
Deus Ex
Hitman

DeusEx, Bioshock, Broken Sword, Gabriel Knight

Dead space, bioshock and silent hill

Heroes of Might and Magic

Pokémon

Baldur's Gate, Bioshock, and Final Fantasy, in that order. :)

Baldur's Gate, Icewind Dale, Neverwinter Nights, Planescape torment
Final Fantasy

I would say The Longest Journey.

Mass Effect, case closed.

Grand Theft Auto.

Portal
Pokemon
L4D
XCOM
Uncharted

Heroes of Might and Magic, The elder scrolls games, Tomb Raider, Baldur's Gate and Icewind Dale games... a bunch of my favourite games are out of those franchises.

For me it's Borderlands.

The Elder Scrolls, Bioshock, Mass Effect, Fallout, Diablo.
All kinds of fantasy or sci-fi.

I will be more original
Trackmania

The Legend of Zelda
Metal Gear
Dead Space
Resident Evil
Silent Hill

Half Life (most things Valve makes), KotoR (most things Star Wars), Tomb Raider, too many to think of off the top of my head, there have been disappointments. I'd put Command and Conquer up there too for example but the last game was a disaster, same for Mass Effect, loved the first 2 and then the 3rd broke my heart., the first 2 Gothic games were fun diamonds in the rough, and so on. There are many such cases.

PS. I don't get Zelda, I think it's highly overrated.