I love Daniel Smith Water Colors and use them exclusively in my work. My favorites are the PrimaTek colors:
"Our exclusive PrimaTek colors are unique paints made with pure, authentic mineral pigments that are mined directly from the earth and each one has a story. These colors have captured the imagination of artists for hundreds or even thousands of years. Their diversity is amazing, see the following for details about some of our favorite shades."
They create depth and a richness that can't be achieved with other paints! - and No I do not work for them ;)
Anyway, these are amazing but can be costly so I thought I would pass along the following ;)