What is the best chemical for pulling water out of the air and where can I get some in semi-large quantities?

"Best" depends on what exactly you want to do. Concentrated sulfuric acid is one of the wildest. Another way is to use dryed salts such as CaCl2, MgSO4, CuSO4 or Na2SO4. Most of these are cheap and easy to get but usually contain lots of water molecules and so you have to activate them yourself by strong heating.

From the above, I only know of calcium chloride.

That's commonly used in some drying agent, like the one you can buy in supermarket to remove the moisture from your house. It is also used in common experiment to ensure an absence of water vapour.

However, I suspect whether it does work with a fast rate since my last agent box performed not very well. Perhaps it is fake!

if you use sulfuric, make sure it's quite conc. it's really crazy stuff i'll tell you that. calcium chloride is definitely one of the best dehydrating agents out there, but as mentioned above, you want to blowtorch it to liberate any water already absorbed

Solid NaOH works VERY well.

as well as any alkali hydroxide. KOH works even better:)

Silica Gell is excellent too, Non toxic, with very little risk of contamination.

 

PolyAcryAmide is also excellent as it`ll absorb up to 400 times its own weight in Water