Echeveria purpusoum , likely white form, or something hybridized off of it. Its unique feature are the ridges and spots on the leaves. The white form also is a redder and paler version of the regular purporosum.

Gonna have to go ahead and disagree with you there...

If this was a hybrid or 'white' purpusorum (that looked THIS distinct) the person who posted it would be getting a new species named after them! "Echeveria D'aira" is actually kinda catchy... ;P heheh

This is 'echeveria dionysos'. It is actually a purpusorum hybrid; where purposorum has dark green or purple margins on the leaves the dionysos has red margins. This appears to be a VERY happy dionysos...

Hope this was helpful :)

My happy 'purpusorum', for reference... :3