Celebrim
Legend
Many, many gamers disagree with this PoV. Some, rather vehemently!Obviously, not all, but still, you might well be in the minority there. . .
FWIW, I am in the (probable) majority, and strongly believe that Fighters in 3e need one hell of a boost, especially at the higher levels.
Fighter is probably slightly too powerful relative to the other classes at up to about 4th level. If the game stopped at 4th level, I'd probably always play a character with at least one level of fighter, and pure fighter would always be an attractive choice. That's a minor concern though because play below 4th level constitutes such a small portion of the game as a whole.
I consider fighter well balanced from 5th to 12th level, which is right in the traditional 'sweet spot' of D&D. Above 12th level though, the spellcasting classes start really taking over because they start getting enough game breaking 5th and 6th level spells (and higher) to be using them in every combat, plus enough defensive magic items/spells that they cease to be easily broken glass cannons. Spellcasters are simultaneously getting more spells per level and more powerful spells (both because spells scale with level, and higher level spells are generally inherently more powerful and game breaking than lower level spells). Fighters just don't have access to anything like Wall of Force, Baneful Polymorph, Power Word:Kill, Mindblank, True Seeing, Find the Path or Wish and the advantages that they do have (a couple of extra hit points per level and a small bonus 'to hit' and damage) just don't compensate for it. It's quite possible to build a cleric, druid, or even high level mage that outdoes the fighter in combat, much less in all the other areas of the game.
Fighters have taken a huge hit in power compared to 1st edition. Meanwhile spellcasters have actually become more powerful in 3rd edition relative to 1st edition. Consider that in 1st edition, fighters got 'double' bonuses for high constitution (other classes topped out at +2 hp per level) and where the only class that could use the 'exceptional strength' table and the only class that got bonus attacks per round. Fighters also had the best saving throw progression of any class, and the best high level saving throws.
So, no, I don't think that the 3rd edition fighter is balanced. It's balanced over a reasonable range of play, but its not even close to balanced at high levels. The difficulty is that fixing that involves changing alot more about the game than just the fighter class. Feats, as the fighter's defining quality, are a good place to start.