A few possibilities for sulfate-free (and silicone-free) shampoo: Renpure Keratin or Argan Oil, Mill Creek Botanicals, Shea Moisture. I know there are lots more, but I don't really use them (I have a gentle sulfate shampoo that my hair prefers).

3a/f/iii
Modified CG since 11/5/11
CLEANSE: CJ Daily Fix, DevaCare No-Poo, CHS Treatment Shampoo
RO: SS Caitlin's Conditioner, CJ Beauticurls Strengthening
LI: SS Repairing Protein Treatment, CHS Silk Leave-In
STYLE: Re:Coil, Curl Keeper, Deva Ultra Defining Gel, Curls Rock Amplifier,Sweet Curls Elixirs Okra Gel and Hard Hold Gel, SS Curl Enhancing Jelly and Firm Hold Gel