1. Gary Locke- Breaks another glass ceiling. Former governor. Fluent in Mandarin. Beautiful family. Geographic diversity. Amplifies foreign policy experience, while taking the spotlight off of Hillary's missteps.
2. Mark Warner- For all of the reasons listed above. Could be problematic having the richest man in the senate run for VP with today's Democrat party.
3. Michael Bennett- Helps in Colorado, where she's weak against Paul. As a former superintendent, he provides a stark contrast to Walker, Kasich and Christie, and will focus on that in Wisconsin and Ohio. Youngish senator, etc. Overall would be a great pick for her, but she might not want to take a relatively safe senate seat and give the Republicans another shot at picking it up.
4. Sherrod Brown- Progressive senator from Ohio. Helps calm the nerves of people who think she's too far to the center. But, like Bennett, would potentially pass him over to keep his senate seat safe.
4.5. Russ Feingold- He has all of Brown's advantages, minus being from Ohio. He also adds more successful foreign policy experience than Hillary, and a vote against the Iraq war to the ticket. He would be higher on the list, but I suspect he's considering a run of his own. He might also be a contender for Secretary of State if Clinton wins.
5. Gavin Newsom- I'm not sure why he's not considered more of a Democrat rockstar. He's got plenty of executive experience, he's handsome, young, articulate, and progressive. If he's not on Hillary's short list in 2016, I'd be very surprised. Also, he was married to Kimberly Guilfoyle, which, besides bringing to light his questionable taste in women, would make for hilarious television if he gets the nod.
If he's the choice, I hope his divorce with Guilfoyle doesn't come up on TV. Guilfoyle is very popular on TV and is a was a tough prosecutor.