Answer:
Looking at the table, Silver is definitely the most conductible metal there. It has the lowest electrical resistivity which means it allows for an easier flow of electrons, and it also has a higher thermal conductivity which means it would exhibit a higher conductivity. Diamond has the highest thermal conductivity, but the electrical resistivity is extremely high and due to its giant covalent/tetrahedral molecular structure (being an allotrope of Carbon), electrons can't necessarily jump around. Diamond wouldn't be a conductor at all.
The most simplest composition and structures provide a higher thermal conductivity. For example, with Diamond, we know that it is a structure made of covalent bonds of carbon, so its thermal conductivity is high.
