I live in Syracuse, NY and I have done Best Buy on BF for the last three years. Since its so cold here, I usually get there around 3am and wait in my car until another person shows up and then I get out and wait. I believe they were opening at 6am though at that point, so I'd probably advise to go at 2am this year like the others were saying.
Our Best Buy hands out the colored paper doorbuster vouchers for all of the big items (computers, camcorders, really good deals, etc) about 30 minutes before opening. One year I stood in line for something I wanted and my mom asked me to pick up a computer deal for her too. Since it was so crazy I just got what I wanted and got out, I didn't have to wait in too long of a line because I paid for my stuff in one of the departments. Then I brought the voucher home to my mom and had her go to Best Buy and redeem the voucher herself when she was done shopping WalMart because I didn't have enough extra cash for her computer. She had no problems when she came back in, but it was still before noon when the doorbusters were still going on.
Also, our store normally has about how many they say the minumum is in the ad. Sometimes there's a few more of some items, but not usually a large amount more, so I definitely advise trying to be in the first 25 people if you're shopping our store.