My PC's are a Ranger and Cleric.
The ranger has basically remained as such. She's maxed out Marksman and carries more arrow types than DC's Green Arrow. She is also my crafter, blacksmith and trap finder.
The cleric was a mistake I suppose. I thought he'd be a good healer, but since I have to put so many points on STR to wear armor he's really a tank. I buffed this even further by giving him a lot of the combat buff skills (resistances to blind, crippling, etc.) and blocking. So he's pretty durable, but not much of a healer.
Jahan I've just kept as the same build basically and just made him better at it. His Rain spell I use all the time and he's a SUPER healer. Now he also summons Ice and Air elementals. Add to that his teleport spell will kill just about anything that's at half health or less. Rain plus Lightning bolt. Loving him.
Madora is my DPS character. She hits and hits hard and all her skills/abilities focus on that as well.
This group works (it's my first playthrough), but if I had it to do again I would have made my Cleric just a Tank and focus on Sword and Shield and all defense.
I won't be playing my second play-through until the next big patch adds the new companions. Based on what they offer will determine what my PC's will be. I already know Jahan and Modora's story, so I'm anxious to see the new companions.