If I had to give personalities based on the names, this is what I'd come up with:
- Dasher: Hasty and sporadic. He leaps before he thinks, is impulsive, and very driven. Although usually victorious, such victory is often a near-miss, and a result of sheer determination not to give up. He often gets himself in situations he shouldn't, nearly avoiding danger. He also makes a bold leader, and is very determined. Often called a wild card. (Personalities similar to Artemis Fowl and Wolverine)
- Dancer: A dreamer. Fluid and elegant. No sharp edges or sporadic chaos. Likes things orderly, but isn't controlled by the need for order. Often well-rounded and balanced. She gets things done, and does them with flair, but doesn't do them for selfish reasons or because she wants attention. She does them because she enjoys doing them or because they need done. She's a firm believer in doing what's right for the right reasons.
- Prancer: a little egoistic (as opposed to egotistic), knows the world doesn't revolve around him, but wishes it would. Doesn't think he's better than the world, but that's because he's never stopped to pay attention. Often showy and ostentatious, in a lovable sort of way. He knows how to charm the crowd. (think Tom Cruise)
- Vixen: Saucy and sensual. If Vixen were a color, She'd be a bold, seductive red. She's the type who was born to turn heads, in a classy sort of way. She's strong and bold, confident in who she is. She's also smart and a little manipulative. She knows how to get things done and she knows how to get others to do them for her. And think it was their idea. But she's not too overpowering to the point where people get annoyed with her, she has a way of finding her way into your heart. (Personality similar to Angelina Jolie)
- Comet: Stalwart. Doesn't quit the task until its completed. Very methodical. Sometimes known to have a temper, but surprisingly able to keep his cool. Although he has his flaws, others often only see perfection. Often driven to do things because they're right, for the good of all. (Think I Am Legend and Froto)
- Cupid: Well, everything I can find for a personality fitting Cupid says a lot the same things as Vixen, but to me, that's not Cupid. I'm torn to whether Cupid is bold or subtle, awkward or completely collected. To me, cupid is like pure love. If Cupid were a color, it'd be deep pink. Soft and comfortable, but whole and complete and subtly moving. Cupid is a friend to everyone. Cupid is loyal (this one can follow the Greek version of Cupid). He's willing to do anything and overcomes great obstacles for the ones he loves. [Not sure if he's more like Hercules (ironically, another mythological tale) or Alma the Younger (that fits the rebel turned good aspect that fits the Roman tales of Cupid)].
- Donner: often called old-fashioned, Donner believes in old-world values and respect. He is a reindeer who likes complete order and is often driven to find it. Donner is a protector, but one with power. Think mafia lord or Thor the Norse god. But in a good way.
- Blitzen: Quick and clever. Blitzen is smart, one you could classify as a genius. He has a short temper and sharp tongue, and is often an instigator. He's a major player in revolution, which isn't always a bad thing. He's innovative and resourceful, and doesnt back down, even when the odds are stacked against him. Think Indiana Jones meets Marty McFly.
- Rudolf: the underdog who let it get to his head, in my opinion. A little too famous.
I guess under these descriptions, I'm definitely leaning towards Comet being my favorite. With Dancer taking a close second.
This site also has a summary of what each character's personality would be, but I didn't follow too closely with what they said.