My most hated big box chain at the moment is Walgreen's. I hate them for demolishing my beloved Kahiki Inn in Columbus, a building that was on the National Register of Historic Places. Walgreen's violated their own policy of not demolishing historic properties by tearing down this wonderful building.
Rite Aid was my most hated chain, but their stock has dropped signficantly and the wind has been taken out of their sails, I am happy to report . Here's to them going belly up!
So what is your most despised chain.