Walgreens seems to be the best, very pure. I don't know any in particular to avoid.

Dr Clark has stated All major companies spill amounts of gasoline by products from the oiled pumps and equipment, and that no commercial water is "pure".
She recommends making your own with a home distiller from tap water.

This is the very best way to go, yet it does take more of an effort, as with all good things.

Peace,
m