Which is the most deadly and why ?

Pride. Because it gives birth to al the rest.

Well, pride was the one that took out Lucifer, but greed has been doing a number on earth. Greedy and corrupt leaders ruining the countries they are supposed to protect.

Pizza. Makes you fat.

Greed. Money is the root of all evil.

Sloth.

I can't be bothered telling you why.

Now go away and let me sleep.