Our group had 4, but picked up one more after the first chapter.
1) Dwarven ranger/rogue. One level dip in rogue, the rest ranger, axe and shield meatgrinder. Giants? Pfftt.
2) Human cleric of Sarenrae. Platemail and scimtar, Healing and Fire domains. High AC and survivability as a frontline backup, tons of healing, and minor blasting. The cleric casts Fireball!
3) Elven Wizard. Lots of fun for wizards. This one focused on Spell Penetration and Persistant/Bouncing spell. He WILL land that crucial spell when you need it. He just got Staff-like Wand, so there's that.
4) Human Bard/Fighter. Spring Attacking/Disarming/Tripping Rapier master, who is the faceman of the group and mega-buffer.
and the group was made all the better by adding:
4) Half-elven Druid of Gozreh. His perception is better then Spider-Man's danger sense. He can actually detect invisible foes just from the Perception roll. No animal companion for him (nor the ranger), but he's a summoning specialist and an incredible fill-in for all the other party roles. Good battlefield control, good blasting, good healing, wild shaping utility/scout/combatant, he can fill in for anyone in the sort term.
Note every party member except the wizard can heal, and with his UMD the wizard can also use wands of nearly anything. And with his Staff-like Wand, he's got a quiver full of them.