My Armor Break Tier List (not ordered). S being part of main combos and forces your opponent to essentially never breakaway, and C is you're better using D2.
S (no order):
Erron, Geras, Jade, Kabal, Shao Kahn, Kano, Kung Lao, Kotal
A:
Skarlet, Kitana, Kollector, Cetrion, Noob, Baraka, Raiden, Sheeva, Cassie, Spawn,
B:
D'vorah, Jacqui, Frost, Jax, Fujin, Nightwolf, Sindel, Shang, Terminator, Joker
C:
Sonya, Johnny, Robocop. Scorpion, Sub Zero, Liu Kang