What is the best brand of teeth whitening trays?

I just got my braces off today. :) I am going to whiten my teeth so what is the best brand of whitening trays (the plastic ones filled with gel, not the flimsy sheets with gel lining on the inside) and how much do they cost on average? Also, have you heard about the 2-day whitening strips? Do they work, and how much do they cost?