Tide: If I find a good deal on alternative detergent, I buy it. But I always long for my Tide. Yes, its the most expensive in the grocery store but it works the BEST. It doesn't fade my clothes; therefore, they last much longer! Additionally, it gets most of the stains out without help from pricey stain removers. I think these two qualities make it worth its price.
Those are the only ones I can think of so far. I'm not loyal to too many brands for many reasons. I like to shop around until I find the best product and, in my opinion, these are the best of the best.
What are some of your favorites.