Where can I find a list of enzyme cofactors and/or co-enzymes, ordered by how common they are?
For example, $O_2$, $H_2O$, $ATP$, $ADP$, $NAD$, should be ranked in the first places, because they participate in most reactions.
Many metals also serve as prosthetic groups in enzymes. They include- Magnesium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Molybdenum.
FeS clusters are also an important part in many important enzymes in mitochondria and plastids.
coenzymes are organic molecules that are required by certain enzymes to carry out catalysis.