Dreft is what I plan on using its for babies.
I used dreft for my first but it got expensive to keep buying him his own detergent so we started using the regular detergent on his stuff as well and he was fine. As long as your baby doesn't have sensitive skin, whatever you use should be fine after a month or two.
I've heard to use dreft but if you don't want to get special detergent use the all brand detergent that has no fragrance or dyes which can be used for the whole familys clothes
I use Dreft or All free and clear
My husband has sensitive skin, so we already use Tide free and clear, and the clear Downy for fabric softener. That's what we plan on using for our baby. No need for more expensive stuff. :)
I bought the tide free & clear for sensitive skin/fragrance free. Its white with a blue cap! I used that to wash all my son's baby clothes! :)