As Part of Ubisoft Black Friday Sale you can get Watch Dogs and a number of other games free with a full price purchase. The Australian store has this deal too (with some better discounts as well) but doesn't have Watch Dogs available as a free game.
The cheapest game you can buy to get Watch Dogs free is Lara Croft and the Temple of Osiris pre-order (releases on December 9) for US$17.99.
To purchase off the US store you need to use a VPN. I used Hola Chrome plug-in and set the region to US.
I first tried using PayPal but that failed then I followed these instructions and paid directly on the site: https://www.ozbargain.com.au/node/143792
The instructions that worked for me are:
1-Added Lara Croft to Cart
2-A list of free game is shown but doesn't list Watch Dogs, hit back and click on Watch Dogs and you can add it to cart for free, or search for it and it will be discounted to $0.00 as well and add it to cart.
3-Disable javascript in your browser.
4-Go to checkout
5-Login with your e-mail and password.
6-Now just fill the fields with your payment informations. I used a fake US address (Google headquarters). Also tick Accept terms and conditions
7-After doing that, you will not be able to click the confirm button because you disabled javascript. Just click on the last field and press enter.
8-Then you get your order and payment info summary. Press the confirm button.
9-Now just wait for the confirmation e-mail.
Watch Dogs is added to your account immediately for download, and I presume Lara Croft will be added on release.
I'm not sure if Watch Dogs is meant to be free since it doesn't show up in list after adding the first game. It could be an error and will be removed or could simply be an error that it doesn't show up in the second free game list.
No more Ubisoft for me. Buggy games, always online DRM, that dreadful Uplay thing, forget it.