What would you consider to be evidence for God?

[Kingpin]

But Vic, his face is there!  I mean come on!  

I'm glad you mention revealing himself.  That's an important point.  Revelation about someone comes about when that person speaks or communicates in some way.  I can use biology and chemistry to study you and your physical makeup but I cannot get to know you unless you speak and reveal something about yourself.  The Christian worldview asserts that God revealed himself in the person of Jesus Christ.

And dog butts. Can't forget the dog butts!

.....who I've never met, seen, or heard from and only know about from other people and dubious sources. Not very unambigious is it? Especially considering the OTHER 20+ major religions.

Of which you must apply the types of evidence listed above and make a judgment.  I believe that Julius Caesar was a real person but I have never met, seen or heard from him and only know about from other people and historical documents.  You say dubious sources, but I know very few scholars who would deny that a person named Jesus of Nazareth existed and was crucified by the Romans under Pontius Pilate.  Where they start to disagree is the resurrection.