My current group is right on the money - one cleric, one wizard, one rogue, and one fighter. Just the way things ended up; we didn't really plan it that way.
We have more than 4 players but we still have some holes. We don't have any dedicated fighters nor do we have any rogues, but several characters have broader roles and fill in for parts of the missing areas.
We have a:
A Fighter/Cleric
A Ranger
A Paladin/Rogue
A Wizard
And a Sorceror
We are 3rd Level right now. The cleric is my character and has one level of fighter. The cleric and the ranger together share most of the fighter role. The ranger and the paladin/rogue (The GM allowed the player to freely multiclass between rogue and a slightly modified paladin due to the character concept which is a paladin of Masque) together share the rogue stealth and skill role. The two arcane casters have not played with us yet but will be beginning next game and should fill the spellcaster niche.
So we are far from the iconic party, but our bases are mostly covered in one way or another.
Our Party: Druid, Ranger, Fighter, Rouge, Pirate/Monk (odd, yes, but an amazingly deep character). We have a severe lack of magic this time around (this is the third in a series of interrelated cmpaigns), but that is partly becuase previous campaigns have been magic heavy.
F Hobgoblin Fighter
F Human Barbarian/Fighter (going for Dragon Disciple)
C Aasimar Cleric
C/W Human Cleric/Wizard (going for Mystic Theurge)
R Human Bard
W Human Sorceress (me)
The other one (level 13, still active)...
F Human Psychic Warrior/Psionic Weapon Master
F Human Cleric/Fighter/Sacred Fist
C Elf Rogue/Cleric (me)
R Human Rogue/Fighter
W Elf Wizard/Elemental Savant
F(C) Dwarf Monk (deceased, will be replaced by a Druid)
And the one before (level 15, pretty much retired)...
F Human Ranger/Fighter/Shadow Dancer
F Drow Fighter/Order of the Bow Initiate
C Dwarf Cleric
R/W Halfling Rogue/Wizard/Arcane Trickster (me)
C/W Human Fighter/Psion
In all cases we seem to have the basics pretty well covered. The new party mainly lacks a trap finder.
The letters at the start are meant to point out the iconic role ((F)ighter, (C)leric, (R)ogue, (W)izard).