Water

Here are some facts.

Viscosity is a measure of fluid resistence to deformation by shear / tensile stress. Confused?

Make a comparison between cases of a guy take a dive into a swimming pool and a quicksand.

We may say that theres a no problem for him to happily swim back and forth but its very unlikely to move freely in a quicksand.

Viscosity is measured in cP (SI unit). cP stands for centiPoise where Poise is taken from a scientist named ... well... lets just call him Mr.Poise. Water at ambient temperature is taken as the datum = 1cP.

Anything below than 1cP is called superfluid. Opss...sorry i messed up... Superfluid will achieve 0 cP at a low temp. How low? Ask mr.google. I dont have time for that  now. Haha. Why on earth do u need superfluid in your daily life? Theres no day-to-day use of superfluid other than to make studies on quantum physics - to investigate the effect of gravity on matters.

Since the title is water, water is also a newtonian fluid- fluid that behave in accordance to newtons laws. Well u do remember mr.newton right? He's not an antivirus developer. Thats Norton. The closest to it is Horton the elephant by Dr. Seuss. Newton is the guy got hit real hard by an apple on his head he got an idea to study what we now call gravity. (i think its not fair to say mad old newton founded gravity. Of course back in those day people did realize all matters fall down to earth). Pretty damn sure he made engineering university students suffer until now. However, thanks to him, engineering in practice does need his theories to measure gravitational pull on masses.

What else... Well yeah, water contains hydrogen ion (+1) and oxigen molecule. In order for the ions to get in balance is to merge together forming what people fancy the name H2O.