A good fighter can still beat an average wizard if he plays his cards right, though.
if the wizard is using just the PHB, and the fighter has EVERY splashbook available, I still feel like the fighter would be in a hopeless position.
Wizard get's Time Stop, Wizard always wins :p
that's why 4e is both superior, and inferior. On one hand, everyone is about equal in power for what they do. On the other hand, everyone is about equal in power for what they do...haha
Each class works in a totally different way
I also have to disagree with that. Fighters/Barbarians/Monks are going to work just about the same. Barbarians get to rage, though, and slightly more mobility. Monks get more mobility, which also means they can't use their main class feature... Monks in general are just really bad in 3.5e.
In the end, though, most people are going to play their turns as a slight variation of "I power attack the gnome for ... 16 damage".
Casters have less of that problem, but many of them share the same spell lists. Mechanically, their only difference is (usually) the number of spells per day, and how fast they access new spell levels. some prestige classes give spell-like abilities or class features that allow you to change things up, which is good, but most prestige classes are fairly lacklustre.
speaking of prestige classes, many prestige classes, especially the ones that merely specialize a base class, can often be done better using the base class, making it a whole "what's the point" situation. Sure, there is the flavor of the class, but why can't you add that flavor to your base class? What separates a duelist from a rogue, or even fighter, besides the name (and the fact that duelists get class features easily replaced by feats :p).
That said, Psionics is really fun to play. The Psionic classes, while limited, offer a variety of different ways to play (psychic warrior plays different from soulknife plays different from lurk, while all being melee type classes, although the lurk is more of a rogue than a fighter), but Psionics gets a LOT of hate for being "overpowered" (false, as I can tell you from first hand experience playing the only psionic character in the party many times :p).
Also, Tome of Battle helps martial classes a lot...by making them play like 4e classes...
Too bad nobody ever wants to play 4e with me. I feel like it could be a lot of fun, but everybody I play with has this dire opposition to it for not being 3.5e, and most admit to not even reading the 4e books
I'd say both versions are equal, depending on what you want to do. 3.5e works better for Lord of the Rings world-changing conflicts against Eternal God-Terrors and high magic adventuring, while 4e is more for Beowulf like heroics, battling fearsome yet local foes.