Try Aubreys Organics, get the one for dry hair; you can get it from Rainbow foods on Richmond road, the Wheatberry on Main St. or Loblaws near Algonquin College.
It's totally sulfate-free and petroleum-free (MEA, DEA, TEA) with things like cat-tails for lather(the plant), sarsaparilla-root (yes the real root-beer ingredient) for shine and smell etc.
You can actually eat this shampoo, but don't. I wouldn't recommend eating "head&shoulders" :) because all commercial shampoos really are strong petroluem acids that break down and dry your hair and scalp.
I've been using it now for three years, my hair smells great, everyone who smells it says so, really and you'll never have dandruff again.