I actually played Pathfinder last night. I think this session could be called a microcosm of 3.x.
So we were in a cave. Not just any cave, an evil cave, a cave so evil it oozed acid from the walls. We are all level 5, I was a paladin, and my companions were a ninja, a cleric/wizard, and a bard. After traversing a pit of acid by jumping from column to column, we came across a black dragon, foul with evil and insane from time alone in the cave. He dropped behind us, spewing acid. My paladin, being the holy avenger smite evil type, charged the foul beasts, yelling at his companions to clear the wall in the back of the room so we could escape. The dragon grappled me next round, and jumped into the pit of acid we had just traversed. Instead of attempting to break his grip, I let go of my sword and shield, and started pummeling the dragon. As a paladin, I could use my healing powers on myself freely, so I could stay in the acid for some time. Seeing that I wasn't letting him go, the dragon then took to the air, and flung me off onto a ledge. Feeling heroic, I immediately ran and jumped back towards him, and rolling exceptionally well, managed to grab onto him again. By then the dragon was low in hit points, easily killable with one more blow from me, he attempted a barrel roll to dislodge me, and the DM said I had one final attack before I fell. I picked up my dice and....
rolled a 1.
I fell back into the acid pit. The wizard/cleric then cast magic missile and killed the dragon. Later on we fought a shadow and I took 5 strength damage, rendering me quite useless till the wizard/cleric could spend the night to cast lesser restoration.
Basically, 3.x is good for fighter types if the DM is good and you are a crazy son of bitch, just like every other game. The mechanics are biased towards casters, but if you are creative and crazy, you can make your mark as a fighter. That being said, if were playing D&D, I'd rather play 4th, or some other system entirely.
On a more practical level, if you want to play a fighter, play a paladin, they are pretty much mechanically better in every way.
However, the wizard will start to show you up very quickly.