It looks like toysrus.com is offering free shipping on orders of $100 or more. Video game hardware, software, and accessories are not included in this offer.
However, if you really want to get out of paying for shipping, I assume you can order non video game merchandise totaling over $100 in addition to the video game stuff you needed.
The shipping will (should be) free. Then, on your next trip to a B&M Toys R Us, you can return the non video game stuff for a refund.
Ok, it is a lot of work for a little bit of money, and somewhat unethical. But it is a way for some to go.