I find Vhaidra the best amongst the Original Characters because she is not drop dependant. Dorn might be a viable option just because of his massive melee potential, but you have to get to level 8 to realize that potential. Vhaidra will focus on Unarmed Combat and Piercing Strike, with a little Combat Reflexes, Improved Critical, Death Blow, and Sprint sprinkled in. Here is the order I go about things with Vhaidra. The order you do the levels will go by your own feel for the game, or if you find a more optimal order, all the better for the run!

1st Level (Tradeway): Stunning Blow x1. This is kind of a throwaway point. I find Stunning Blow useful at the start of the game and in a limited fashion in later levels, so it's useful to have the ability in some form, even if it's at the lowest level.

2nd Level (near First Key Chest): Piercing Strike x1, Toughness x1. Piercing Strike is huge... At max level, it will triple your damage output. Toughness is kind of a throwaway point, but it will certainly help you survive until Baldur's Gate and throughout the Hands of Glory mission.

3rd Level (Wayfork Inn): Combat Reflexes x1, Improved Critical x1

4th Level (Purple Wyrm Inn, buy 2000 exp): Unarmed Combat x1

5th Level (After Hands of Glory. Then be sure to buy 4000 exp): Iron Will x1, Piercing Strike x1, Sprint x1. Iron Will is kind of a throwaway point, but I like the extra magic regeneration power over the couple more magic points you'd get with Willpower.

6th Level (Bloodmire Manor first floor): Unarmed Combat x1

7th Level (Bloodmire Dungeon 1): Combat Reflexes x1, Piercing Strike x1

8th Level (after Firewind Manor): Unarmed Combat x1

9th Level (Purple Wyrm Inn, buy 8000 exp): Improved Critical x1, Piercing Strike x1, Sprint x1

10th Level (after Sleyvas): Unarmed Combat x1

11th Level (after Jade Octahedron): Combat Reflexes x1, Piercing Strike x1

12th Level (after Diptolpt): Combat Reflexes x1, Sprint x1

13th Level (after Luvia): Death Blow x2, Improved Critical x1, Iron Will x1, Sprint x1

14th Level (after Air Foundation): Combat Reflexes x1, Improved Critical x1

15th Level (after Fire Foundation): Death Blow x2, Improved Critical x1, Toughness x1, Willpower x1. Those last two points are throwaways. Use them however you want

16th Level (after Water Foundation): Death Blow x1

All levels obtained after this point, just take the level-up but don't distribute any points. You're done!