After college I lived at home for a couple of years and used whatever kind of soap my mom bought. When I bought my first house I started buying generic cheap laundry soap. We had t-shirts with our school name on them that we wore once a week. One day I noticed that one of the other teacher's shirts was way faded compared to mine. I asked her what kind of soap she used. She used Tide. That showed me that I never wanted to use Tide, it wasn't worth the cost.
I used coupons to buy some Dreft when I was pregnant. I had planned to save that expensive stuff for just baby clothes. After the baby was born it was easier to wash all the clothes together and no one seemed to be bothered with other soaps. I did find out that Dreft did work well on stains so if baby had a particularly stained up clothes I would throw a capful in with the load. (When they began eating solids, oh how I hated clothes with bananas or avocados on them!) Dreft did smell really good when I used it! I sometimes bought Target brand like Dreft for this. When we moved I donated about half a bottle of Dreft because I used it so infrequently. When we lived in MN I started buying Xtra at Walmart for most of our laundry because that was the cheapest and easiest (only 1 1/2 hours away).
When we began using cloth diapers for Lamb 3, they warned to use more natural soaps, not soaps like Dreft. So I bought some expensive soap online and only used it for diapers. When that was gone I discovered Biokleen free and clear and bought that for diapers.
Last year I decided to make my own laundry soap. I bought the supplies and made it regularly and used it in almost every load. A few months after that Lamb 2 started to get a rash. In a process of elimination I decided to use just free and clear laundry soap, not Xtra, not homemade laundry soap. We still don't know what causes his rash and he still occasionally gets it, but it is less when I use free and clear.
Then I discovered Sun free and clear and it is a little cheaper than Xtra, possibly that is because of living in the West now. I use Sun on almost all loads. I can get Sun at the grocery store, don't need to go to Walmart. I still use Biokleen free and clear on our loads of underwear and socks. Sometimes stores here have Biokleen on sale and I only use a small capful so Biokleen lasts me a long time. I still have lots of the supplies I bought to make homemade laundry soap so I still use that on loads that don't have any of Lamb 2's clothes in them and on cleaning rags.
What do you use for laundry soap?