The Alberto VO5 range is probably the cheapest shampoo/conditioner you can find at drugstore (retails for at most 99 cents) - While their shampoo is pretty generic of any that contains SLS (cleanses well but makes my scalp itch), I really love their no-frill and functioning conditioner.
Out of the few I have tried, they are all light (no -cone to make your hair dull after prolonged usage), potent (detangling well), a little runny (so they get smoothed out easily) and smell fresh and yummy. My favorite scents are the Herbal Escape Free me Freesia and Tea Therapy Blackberry and Sage Tea.
P.S. I stock them up whenever CVS prints of 2-dollar off shampoo/conditioner purchase, so I get two or three (during sale) of them for...free.