I used Dreft with my first because they make you feel like their skin might fall off if you don't. Then I switched to a free and clear which I like so much that I use it all the time now so I didn't have to switch with my 2nd and don't plan to with this baby. My DS actually has really sensitive skin but detergents don't seem to make any difference to him that I've noticed.
MIL bought a giant thing of Dreft for DS's clothes, that got used all of maybe five loads... then I switched to regular detergent. I washed the first bit of Wynn's clothes in something or other free and clear (I wanna say Purex or something equally cheap because that's how I roll) and if she doesn't have skin issues we will switch to regular detergent, because everything in our house gets washed in the GIANT washers at the laundry.