There's certainly many views on the best form of water for consumption;
personally I believe that distilled water is only good for short term cleansing as it may help pull some toxins out.
However distilled water is thought as dead as it is stripped of minerals. The concern is not so much from the lack of minerals (you can get plenty from food): the problem is that distilled water may be hard to absorb properly and hence require energy;
distilled water molecules are often clumped together irregularly and not as recognizable as pure spring water. Water needs specific minerals to help structure the water that is recognizable to the body
The best water would be natural spring water that started as rain and through splashing against rocks it mineralizes itself - also the sunlight provides wide range of wavelengths that "Vitalize" the water - also oxygenation of water would occur in a natural spring source.
This process arranges the water molecules in such way that is very absorbable and healing.
A good filtration system is fantastic to remove pollutants, but an additional step to energize the water can make all the difference.
Gadgets like the vitalizer plus are great (I have one, a bit expensive though ~$450) - some people opt to put something that has life force and minerals in the filtered water and even put it outside to absorb the sunlight.
If you can afford the vitalizer it will provide infrared, minerals and oxygenate the water - the difference is night and day (as being very light and quenching)