God. God is the uncaused cause
Tell me why God must be the uncaused cause. If we're going to claim that God can be an uncaused cause, then there's equally as much right to claim the Big Bang was the first cause too. The God excuse is exceptional at explaining the unexplainable in an unexplainable way. Theists cover their God with all sorts of rules and exceptions to prevent his existence being torn apart, but it's the fact that it's the humans saying "God gives us free will" etc.
This is said about him to protect his existence, why are we, as advanced a society we have become, still creating excuse to protect the existence of something with no evidence to support it? Madness.