A recent observation:
Back when I first played Neverwinter Nights, I played through the game as a bard/rogue. I always had a barbarian NPC to protect my back, and I ended up learning summoning spells so I could get the extra oomph in fights, and even then, several fights were pretty tough.
I played through it again with a wizard, and found the same thing.
I played through it again as a fighter, just recently. Although I ended up getting only 12 levels of fighter, the rest in barbarian, that's because I ran out of fun feats to take. On the other hand, I realized about a third of the way through the game that I didn't even need an NPC ally, and was able to complete the game (along with killing some uber dragons and such along the way) with only the one character.
Obviously, there are differences between CRPGs and PnP RPGs. Still, it surprised me how powerful a fighter character could be.
I do agree that certain archetypes are hard to achieve with fighters; for this reason, I advocate a lot greater skill flexibility. Allow them to take diplomacy, spot, and so on.
Daniel