Amazon. Currently they have Tide plus Bleach 50oz (26oz) for $5.99 and then you can also clip the $2 off coupons to make it $3.99.
This deal qualifies for FREE shipping. This is a pretty good price for laundry detergent...AND...you don't even have to leave your house! Hurry before it goes away! Also, make sure you check out other Tide products, as they may qualify for the $2 off coupon as well.