My personal tier list, based on online play
1. Jax (ground pound turtling owns, very cheap, I rarely select him now because I know he's frustrating to fight against and I dont want to drive away my online compitition, there's not much of it as it is)
2. Lui Kang (low and air fireballs, good uppercut, powerful wakeup game with the bicycle kick, a strong turtle fighter)
3. Mileena (sai spamming is hard to counter with certain characters, plus she has hard to counter high priority jump kicks and sweeps, good uppercut)
4. Kitana (high damage projectile, high priority female ninja kicks, good uppercut)
5. Kung Lao (strong uppercut, dart kick can be very effective, crouching low kicks good at getting out of pressure, spin)
6. Shang Tsung (perhaps the best jump kicker in the game, the easiest for me to get a friendship with, and with his fireballs he's a strong turtler)
7. Scorpion (can be very confusing with his teleports, that ninja roundhouse)
8. Sub Zero (get caught with his projectile and lose a lot of life, slide is hard to punish online, he's my preferred fighter against Lui Kang and Mileena players)
9. Raiden (teleport is very useful, so is his torpedo against certain characters)
10. Reptile(it's about invisibility and turtling with the forceball and acid spit, acid spit is very fast and hits high and so is good against jump kicks)
11. Cage (I rarely use this guy but his cross-up nut punch is good at catching opponents who are not thinking, shadow kick is also good counter move)
12. Baraka (again I rarely use him so he doesn't rate high on my list, great jump kicker though)