[3.5 Core] Boosting the fighter (PEACH)

[NeoSeraphi]

Barbarians get rage. The Extra Rage and Extended Rage feats basically allow them to rage the entire combat, every combat, giving them +2 to attack and damage, +2 to fortitude and will saves, for -2 AC. At 11th level, the bonuses become +3, at 20th level, they become +4. Starting at 14th level, they also gain +4 on saves against spells like Dominate Person and Hold Monster.

You also forgot that delicious +80 HP at 20th level. Extra hit points, as well as the highest hit dice in the game and a terrible but still better than nothing DR 5/- make the barbarian a much better damage soaker than a fighter.