Here are mine
MK: Liu Kang
MKII: Johnny Cage
MK3: Sub-zero
UMK3: Liu Kang
MK4: Scorpion
MKDA: Scorpion
MKD: Sub-Zero
MKA: Created Fighter
MKvsDC: Batman
MK2011: Kratos

MK: Sonya
MKII: Kitana
UMK3: Jade
MK4: Tanya
MKDA: Li Mei
MKD: Jade
MKA: Jade
MK9: Jade

MKDA: Frost.
MKU: Frost.
MKA: Frost / KAK Emerald.

MK: Scorpion
MKII: Kitana
MK3: Smoke
UMK3: Kitana/Kabal
MKT: Johnny Cage
MK4: Sub-Zero
MKG: Cyrax
MKDA: Kitana/Kenshi/Cyrax
MKD: Kabal
MKA: Hydro *KAK*
MKvsDC: Scorpion
MK2011: Kitana/Smoke/Skarlet

MK: Kano
MK II: Baraka
MK III: Kano
UMK III: Reptile
MK IV: Reptile
MK:DA: Nitara
MK:D: Baraka
MK:A: Baraka/Reptile/Nitara
MK 2011: Kano

lol

MK: Sub-Zero
MKII: Kitana
MK3: Sektor
UMK3: Kitana
MK4: Fujin (In reality I played the hell out of all the chars)
MKDA: Kitana (Kenshi equally as much though)
MKD: Ermac
MKA: Fujin (Kitana equally as much though)
MKvsDC: never played (would have been Kitana)
MK2011: Kitana (see the link in my sig)

MK: Scorpion/Raiden.
MKII: Scorpion/Reptile/Kitana.
MK3: Cyrax/Sektor.
UMK3: Scorpion/Reptile.
MK4: Scorpion/Quan - Chi/Fujin.
MKDA: Scorpion/Reptile/Cyrax.
MKD: Scorpion.
MKA: Scorpion/Chameleon.
MKvsDC: not yet played.
MK2011: not yet played.

MK:sub zero
MK2:Raiden
MK3:Cyrax
MKD:Darrius/Tanya
MKA:Rain/Shinnok
MK9:Kabal

1:Kano
2:Jax
3:smoke
UMK3:H.Smoke
4:Scorpion
MKDA:Shang Tsung
MKD:Baraka
MKA:Noob
MKvsDC: MK:Baraka DC:Captain Marvel
MK2011: Sektor(Human)
Injustice:Cyborg

MK: Liu Kang
MKII: Baraka
MK3: Sindel
UMK3: Sindel
MKT: Motaro
MK4: Quan Chi
MKDA: Kitana
MKTE: Bo' Rai Cho
MKD: Bo' Rai Cho
MKA: Karina
MKvsDC: Baraka
MK2011: Smoke

MK: Cage
MKII: Cage
MK3: Cyrax
UMK3: Cyrax
MKT: Cage
MK4: Cage
MKDA: Cage
MKTE: Never played.
MKD: Sub-Zero
MKA: Reiko
MKvsDC: Captain Marvel
MK2011: Cage

EDIT: I didn't know I did this already. lol

1. Raiden
2. Kung Lao
3. Kung Lao
4. Quan Chi
DA. Kung Lao/ Kano
D. Sub-Zero
SM. Kung Lao...
A. Kung lao...
MKvDCU. Green Lantern
2011. Kung Lao...

Can you guess who my favorite character is?
*Gently stares at top left of post, then at bottom.*

MK1, 2, & 3/U/T: Liu Kang or Scorpion
MK4/Gold: Noob Saibot
DA & Deception: Sub-Zero
Armageddon: Reiko or Sareena
vsDCU: Liu Kang or Green Lantern
MK9: Johnny Cage and Jax ("and" because I only play Tag)

MK1: Raiden
MK2: Raiden
MK3: Nightwolf
MK4: Tanya
MKDA: Nitara
MKD: Raiden/Kenshi/Nightwolf (?)
MKA: Nitara
MKvsDC: Batman/Raiden
MK9: Raiden/Scorpion

MK: Cage
MK2: Cage
MK3: Cyrax
UMK3: Stryker gets a bit more use because of the gun spam
MKT: Cage
MK4: Quan Chi
MKDA: Kenshi/Cyrax
MKD: Kenshi/Li Mei (and Goro on the Gamecube)
MKA: Cyrax/Stryker
MKvsDCU: Sonya
MK9: Cyrax/Kenshi/Cage

Also I play as Sub-Zero about as much as any of these characters, in every game except MK9. I don't find him very fun in that game.

MK1: Liu Kang or Scorpion

I first played Mortal Kombat one when I was very young, and I always picked Liu Kang because he looked like my dad when he was younger. Liu Kang is still my best character and my first choice when playing through the ladder, but I tend to pick Scorpion more now because my little brother uses Liu Kang as his main.

MK2: Liu Kang or Baraka/ Reptile or Scorpion

Liu Kang is my best like in the first game, but I also like using Baraka while playing on the ladder. I tend to use Reptile or Scorpion more when fighting my brother or friends though.

MKT: Goro, Reptile

I don't play MK3 or UMK3, instead I prefer to play Trilogy. Goro is my favorite character to play as but Reptile comes in as a close second.

MK4: Goro

I'm not overly fond of this game but when I do play I always use the code to play as Goro.

MKDA: Reptile

Deadly Alliance was the game that got me back into MK and Reptile played a big part in that.

MKD: Goro

After playing Deadly Alliance I learned that Goro was playing Deception and got it as soon as I could, and I wasn't disappointing.

MKA: Goro, Reptile, Shao Kahn

Goro is by far my best character in this game, and any MK game in general. His playstyle is awesome and I wish he still played like this in MK9. Reptile and Shao Kahn are two other characters I play as frequently.

MKvsDC: Shao Kahn, Scorpion

By far the best version of Shao Kahn gameplay wise, though he could use his classic taunt.

MK9: Goro, Reptile

I play as Goro the most and I've gotten quite good with using him despite his limitations. Reptile is my main other than Goro though.

MK1: Scorpion
MK2: Reptile/Baraka
MK3: Jax/Kabal
UMK3: Reptile/Ermac
MKT: Ermac/Baraka/Reptile
MK4: Quan Chi
MKG: Quan Chi/Baraka
MKDA: Quan Chi/Scorpion
MKD: Baraka/Ermac
MKA: Quan Chi/Ermac
MKvsDC: MK side: Baraka. DC side: Deathstroke
MK9: Ermac/Quan Chi

If it counts,
Injustice: Joker/Scorpion/Deathstroke

MK1: Johnny Cage
MK2: Kitana
MK3: Kung Lao
UMK3: Kitana
MKT: Kitana
MK4: Reiko
MKG: Kitana
MKDA: Kitana
MKD: Ermac
MKA: Kitana
MKvsDC: MK side: Kitana. DC side: Wonder Woman
MK9: Kitana

MKI: Sonya
MKII: Mileena
UMKIII: Sonya / Sindel
MKIV: Sonya
MKDA: Sonya
MKD: Mileena / Sindel
MKA: Sonya / Mileena / Sindel
MKvsDC: Sonya
MK9: Sonya / Mileena / Sindel

Oh gosh, this is so easy.

Sub-Zero for all of them... Well, until Deadly Alliance and Armageddon then I also played as Frost.

MK: Sub-Zero
MKII: Sub-Zero
MK3: Sub-Zero
UMK3: Classic Sub-Zero
MK4: Sub-Zero
MKDA: Sub-Zero
MKD: Sub-Zero
MKA: Sub-Zero
MKvsDC: Sub-Zero
MK2011: Sub-Zero

Yup.

correction! Regime Superman

Like Luca and IceBaby, I too have mained Sub-Zero throughout them all. Man I love that icey bastard.