re: New York or Los Angeles?

I've lived in both, and I would pick Los Angeles without even a second of hesitation.

I don't think the traffic is that unbelievably bad, especially if you avoid the major highways. If you can drive through something like Olympic Blvd instead, it's actually quite manageable. The only time traffic was killing me was when I went to the beach (Venice was worse from a traffic standpoint than Santa Monica, fwiw).