I am a big fan of Tide's Coldwater powder detergent - I'm using it for the fabric prewash of my current job* because test samples changed color in hot water (shrinkage was identical).
With energy costs UP, I thought I'd pass this on. I use Tide Coldwater for all our family laundry, and it's just as clean as ever. Consumer Reports rated it "excellent" if I recall correctly.
*Click on title to see fabric.