Wow, great options. Tough choice, but...
I would go to Syracuse!
I considered applying to USC. I know awesome people who go to the Annenberg School. I think their PhD offering sounds fantastic. But, while USC is better known -- at least on the West Coast -- from what I've seen, I don't think USC's reputation is going to get you that much further than Syracuse's near anonymity. (If you move back to the East Coast at some point, Syracuse may offer more connections for you anyhow!) For me, USC's rep. wouldn't be reason enough to incur that much debt.
That said, I am really anti-debt. Especially in journalism.
After looking into USC more, I felt strongly that the SoCal area wasn't a good journalism practice ground for my interests, and I wouldn't want to spend two years there. If you already feel like you've spent too much time there, that doesn't sound like a location that will encourage you to continue for your PhD. Meanwhile, Syracuse nets you great New York connections and gets you back on the East Coast.
I wish I had known more about Syracuse before I applied to graduate schools. It was off my radar until recently, but it sounds like a great up-and-comer in the top J-School rankings. The opportunity to be part of building their reputation would be exciting. It's nice that, compared to other schools, I haven't heard one bad thing about Syracuse. Their program offerings look stellar. It'd be a win to go there. (I still hope you get funding!)
Maybe now is a good time to enquire about how Syracuse's one year program can still support your PhD aspirations? I'm sure there are things you can do, but I haven't researched it much myself. Judging from their program titles, though, I'm not sure two years in a "print journalism" track is going to make you more Communications PhD-ready than one year at Syracuse; their program sounds more comprehensive and possibly comparative, which is probably better prep! If you have a relevant undergraduate degree as well, I wouldn't worry so much about your graduate school choice as long as you have focused aspirations.
How long do you have left to decide, and are you interested in Columbia if you get off their wait list? Also, what does your intuition tell you?