Which block is the most important in Minecraft?

Which block is the most important in Minecraft?

[Own opinion!] Definitely the crafting table, because you could do without just primitives. And otherwise the wood, because you simply can't do anything without wood.

The most important one without a function is certainly cobblestone. I've built almost every basement wall with it ^^.

Wood, because without it you couldn't make a crafting table or tools. You also need wood for many other things such as steps, printing plates and signs.