What could be the biggest deepest question to ask? and I know this could be too general, but...
What were the conditions of the universe at and before the moment of the big bang. Was our universe generated from the multiverse? Was all matter actually compressed to an infinitely small point? Did time and space exist before the big bang?
Is there some form of life after death?
The U of Virginia study seems to say yes [med.virginia.edu]
Almost definitely. Billions of them.