Worst US/Canadian border crossing

I think the best crossing we've had was going into the US at Sarnia-Port Huron. The officer asked us the usual "Where are you going? Where did you come from? Did you make any stops?" questions, which I answered including a lunch stop in London where we walked the dog. He then addressed our dog that was looking out the window, "And did you leave anything behind in Canada?" he asked her. I answered for her with, "Just a wet spot, officer. If she had left anything else, I would have bagged the evidence and brought it with us." Well, that broke him up, and he was still laughing as he waved us on through. ;)