Amazon wins easily. The DOTD is good for at least one good to great deal a month, and that isn't counting the other random great deals. They match deals from the Sunday ads and from other stores and sites. Their Black Friday sale was better than every other store. $25 is a low threshhold for free shipping, + no tax. The only bad thing is they discontinued the price guarantee.
Does Steam count for this, they had some great weekend deals this year? Stalker, Bioshock, and many more for $5 each, plus the huge year end sale.