I needed to wash my queen size comforter, and I found this place on Yelp. It's right in my neighborhood, and I found it to be reasonably clean and well-trafficked. I went on a Wednesday morning around 10, hoping that it wouldn't be too busy, and I was right. This place had a good selection of washers for all sizes of loads, and while I think $4.50 is about a dollar too much for their large size front loaders, I was happy that I only needed $1 to dry the comforter. That meant I was in and out in less than an hour, and paid less than $6 to clean a queen size comforter. (I brought my own detergent and dryer sheets, but there is a machine that dispenses these things for about $1.25 or less per load.)
I also liked the fact that there was an attendant on duty (but presumably only during the day, as this is a 24 hr establishment).