Update: Please note that some sets have markups at Yoyo so your potential savings could be less.
The last Yoyo.com sale is happening right now. Until December 28, 2014, you can get up to 35% off select Lego CITY Sets at YoYo.com. Free 2 day delivery on orders $49.
Notable sets include Friends Dolphin Cruiser for $59.99 (reg.$89.99) and LEGO City Train Station for $58.49 (reg.$89.99). Respectively, savings work out to be 33% off and 35% off.