People with a stagnant smell: Are you running your cleaning cycle with one cup of Clorox? Mine has a special cycle just for this, and the manual says it should be done once a month.
I've never used anything except powdered detergent in mine. I buy it in HUGE buckets at Sears for $20. For my family of four, I use a bucket in just over six months.
We have the Tromm front loader--never again. The smell has been terrible, and it does transfer to the clothes. Have done every single thing recommended, have contacted the manufacturer, dry the machine out by hand after use, leave the door open, use special detergents, used "affresh" and "stinky wash" periodically recommended by manufacturer to rid the smell, etc., etc., etc. Smell leaves for a short while, then returns.
Saw a consumer report that this is a huge problem with front loaders, especially Maytags.
It actually said in the manual don't use powdered, you couldn't open it after it started because the door locked until the end of the cycle, leaving the door open did nothing for the standing water because there was about an inch of it in the basin and we are on the west coast where that just won't dry out on it's own. You really really need to do your research on these things.

Usually I find something more after I went up stairs.