Gain HE powder. I save imported Persil (Henkel or Unilever) for my work clothes, nearly all of which are 100% cotton, wrinkle free office casual (khakis plus collared shirt). For sturdy cottons and towels, I use either Gain or Tide HE powder. From time to time, Amazon offers a good price on two- or four-pack purchases of Gain HE powder, so I have a several year supply stocked away---not because I hoard it, but because it's hard to find locally and the Amazon deals generally require a bulk purchase. I haven't tried the new concentrated HE powders, because I have a LOT of Gain and Tide HE powder to use up before it would be time to buy powder detergent again (I mean a matter of years).