I see above that there are a lot of votes for Tide and Tide w/bleach in powder, and I agree! They are my favs. I agree with the sentiment regarding powder too. Liquids are easier to use (I worry about powders scratching the surface of my dryer among other things) but I prefer powder, especially since this past winter's second rebuild of a machine I first rebuilt in 1995. It had been used for 14 years with liquid detergent in exclusively cold water. The scum was at least 1/3 inch thick, and it stunk like a septic tank. Grossest washer re-do I've ever done. So, no more liquid for me!
I recently had a pleasant surprise from Fab powder and would recommend that as a great inexpensive bargain. Within the last two months a new scent was introduced here, so my local store put one of the previous two scents on clearance to make room for the new one. They cleared out the scent which comes in a green box, and I got them BOGO, so two boxes for $3.91, less than two bucks a box. I wound up buying 10 boxes.
I gave four to my mother, and she loves the stuff, saying it makes her whites really white. Well, I tried it later on my white gym socks, which I invariably wear at some point out in the garage, and I agree. WHITE whites! It's worth a try if you haven't tried it.