Flagpole.
I drove from Toronto, it took me about 3 hours to get there, no heavy traffic at all. Before crossing the bridge I paid a toll in cash (3.75 CAD) then I got to the US side, told the officer I was flagpoling, he gave me a yellow paper and asked me to go to the office. I parked the car, another officer took my keys. Went inside the office and an officer gave me the refusal paper. Got my keys and the car back and went to the Canada side, showed my documents to the officer (COPR, Passport and refusal paper) and he send me to the office. The system was down so I had to wait for almost an hour, but when the system was back up the process took like 10min. As I said before, there was only one couple before me. The officer asked me for my address and how much money I had in my bank account (she didn't ask me to show proof of funds) she also asked me some questions like if I had committed a crime or if I had dependents (I'm a single applicant).
That was pretty much it, and now I am a very happy landed immigrant
.