I play as Baraka, and Sonia 50/50. I'm better with Sonia but i consider Baraka my main. What does the GB Kommunity consider their mains?
 
If you play as Kung Lao ,Ermac ,Smoke be honest! You shameful son of a gun.
 
Edit: I noticed no one was playing sektor so i tried him out, people have been rage quitting left and right. This never happened to be before when i played baraka or Sonia, probably cause people thought baraka was an easy kill.

Johnny Cage of course.

Noob Saibot is my main man

Jade all the way for me son!

If you pressed me, I'd say Mileena, but I always try to mix things up. I have a table of about five characters that I rotate, but Mileena is who I go to if things get serious. 

Raiden for me. THUNDER TAKE YOU!

I find myself enjoying smoke a lot. But I've been messing around with Kabal Jade and Mileena as well.

I jump between Smoke and Sub-Zero. I'm no professional, and they seem like the easiest for me to use.

I play Ermac the most. I like to play all of the ninjas or just hit up the random select when I don't really care.

Sub Zero. I play as smoke, noob, jax, and johnny cage aswell, but Sub Zero is my go to guy.

Johnny Cage with Reptile as my second.

Main: Raiden (recently switched from Liu Kang) 
Secondary: Liu Kang, Scorpion, Cyrax 
Tertiary: Sub-Zero, Cyber Sub-Zero, Johnny Cage, Kung Lao, Smoke, Ermac 
 
My corner game is, by far, my strongest attribute, which is why I initially played Rushdown Liu Kang. 
I noticed that I had trouble placing them in the corner from mid screen without having to take big risks (Flying Kick is super punishable and predictable, and it's hard to close distance for the B+3, 1, 2 combo), so I switched over to a super aggressive Raiden. It's paid off huge dividends so far with win streaks of 40+ against decent opponents. 
I have a really tough time against Smoke and Mileena, though.

StryPOLICEBRUTALITYker.

Kano mostly. Quan Chi and Sheeva are also in the rotation.

Smoke, although I try to combo and mix it up rather than just tele spam. I just love his speed.

I'm practicing Kitana though, and really enjoy playing her against the CPU, so looking to spend more time there as well. After that I have my eye on Kano, Liu Kang, Raiden, Johnny Cage, Scorpion, Sub-Zero, Sonya...

MORTAL KOMBAT!!!! :D

Seriously though, Ermac, Mileena, or maybe Reptile.

I really like Sektor. His Arcade ending sold him for me "He went to go put on a medallion, his father told him not to wear it - but he did." 
 
Means f*cking business.

I main sub-zero, because he is a great zoner who can rush down as well. Plus, I like the cold, so I think he's a cool character. 
 
(played him in all of the MKs too)

I've been using Kratos a lot, as well as Sub-zero.  They're actually pretty similar to play.

Main: Smoke
Secondary: Jax, Kung Lao, Nightwolf,
on the side: Stryker, Cyber Sub Zero/Human, Scorpion, Jade, Kiatna

Raiden apparently. Never played him in the old Mks, but apparently I'm alright with him, so I stuck with it.

Johnny Cage because of his personality.  No really I loved him so much in the story mode I decided to learn his character and I'm having a blast with him.  A good rush down character with some weak matchups against zoning characters.  Either way I'm glad one of the pros has a lot of advice for him (Tom Brady) so I'm learning a lot.  Can't wait to play this game again!

Don't really have one, my usual characters are Johnny Cage, Barraka, Scorpion, and Smoke though, sometimes I through in a Stryker or Sub Zero in there.

Ermac, cause I'm a little bitch. 
 
Then Striker and Johnny. 

I only play Ermac. Since there's so much tele spamming and random mashing online I feel like I need his force push to keep people honest.

Jade all the way for me son!

Reptile.

I like Sub Zero and Kitana. I suck overall though.

Reptile is my guy 

Stryker/Kung Lao
 
 
Raiden if I need to dish out some teleporting punishing to those noob/smoke/scorpion fools.

I wouldn't say I'm the best with them, but I have the most fun playing as Kitana and Cyrax.

Kitana.

Raiden.

Kabal/Reptile/Ermac

Smoke all the way!
 
But I will mix things up Johnny Cage, Sonia, and Kano.

Stryker, yo.

Sektor, Quan Chi, Shang Tsung, Sub Zero, Noob, Liu Kang, Ermac. In that order of preference.

Kabal. 

Quan Chi, Mileena, Reptile and Sub-Zero in that order.

Kitana. I often play Scorpion if I ever see a Scorpion as my opponent, just for fun.

I really like Sindel, which is odd because I don't think I ever picked her before this game.

Sektor because robot.