In Dragon Age 2 for the PS3, Xbox 360, and PC, a couple of the armor wearing characters can exploit a glitch to get an unlimited amount of armor points.
Using Aveline or Hawke (if you made his role a warrior), equip, remove, and then re-equip a shield at any point in the game. You’ll notice that every time you do this, your armor keeps going up. Keep doing this as many times as you want.
This may be (and most likely will be) patched in the future, so avoid installing any game updates if you want to continue using this glitch.