Carth: best drinking buddy ever!
Bastila: one of the best Jedi I've ever seen
Mission: I highly doubt a teenager a year younger than me would have her own gun and sword.
T3-M4: Kotor's R2-D2. What else can I say
HK-47: Scary yet funny
Jolee: Both a wise guy and a wise man. Not an easy task.
Canderous: Too agressive, but then again, he's a Mandalorian
Juhani: It's a shame the male PC couldn't romance her...without modding.
Overall, I'd say either Jolee or the Droids.