works for me: brand loyal
Laundry Soap - recently abandoned Tide liquid in favor of Costco's look-alike. It works just fine.
Skin Care - about 18 months ago I abandoned Lancome in favor of LUSH. Love love love it.
Interior or Exterior Paint - Behr at Home Depot. Every major holiday weekend they have a huge rebate offer. We've painted the outside of our home, all the inside, and our big red barn all with Behr paint. It's awesome.
Chickadee's clothes - hanna andersson. Beyond cute plus they hold their resale value. I buy used off of e-bay and then I don't care if they get a bit beat up. When she outgrows them, I sell them on e-bay.
For just about everything else, I'll deliberately buy the off-brand, figuring that all those dollars spent on advertising (aka sponsorship of yucky television) are built into the price of the big-name items and I'd rather opt out of contributing to that.