Most common material in the universe I was told that 'water' was the most common material in the universe and I disputed that claim. I was met with the argument that hydrogen and oxygen were the most common atoms in the world so water was as well. If this is true, then how come we can't find water anywhere in outer space? It must be the collection of 2 hydrogen atoms and 1 oxygen atom that is so rare then?
The Big Bang started with about 3/4 hydrogen atoms and 1/4 helium atoms.  Add a pinch of lithium and a whisper of boron.  Supernovae since then have released a lot of helium.  Heavier elements are still rare.

"The most common [molecular] material in the universe" must survive photolysis, radiolysis, and reaction.  Water is poor candidate.

http://www2.astro.psu.edu/users/alex/astro497_7.pdf 
What is out there.  CO is the marker. 
http://physics.nist.gov/cgi-bin/micro/table5/start.pl 
Molecules in space, isotopically and by 
http://science.gsfc.nasa.gov/691/cosmicice/interstellar.html 
http://www.astro.uni-koeln.de/cdms/molecules 
atom count