I'm not fond of the Barbarian's Rage ability. Whenever I roll up a Barbarian character, I think of the character more as a "brick" – strong, powerful and seemingly unstoppable, like…
I don't envision any of these characters (or my own) as being in a battle trance, foaming at the mouth with rage.
The Barbarian's Rage, however, is fairly key to the class in 3.X edition.
What are alternatives to giving a Barbarian a Rage ability?