I recommend Tigi's Oatmeal and Honey shampoo and conditioner. It's excellent for colour treated, chemically damaged, dry, hair. I use it as mine is over coloured and bleached and it's really done it good.
Problem is, it's a little pricey. Usually about £8 for a conditioner and £6 for a shampoo. However, most salon's are stocking Tigi's latest offer, which is the two bottles that are 750ml each, for £14.95. One 5ml pump of each is all you need, and it should last you about six months or so.