Even Richard Dawkins, of The God Delusion fame, builds said book around the concept that God cannot be disproven, merely estimated to be insanely improbable.

Myself, I prefer a certain type of Deism...I can't help but look at all the complexity in the Universe, and think that there is some sort of higher power...although I believe it to be rather vain and self-important to believe that that higher power would have any special interest in us and our little speck of dirt.

Einstein said it better than I can:
"My religion consists of a humble admiration of the illimitable superior spirit who reveals himself in the slight details we are able to perceive with our frail and feeble minds. That deeply emotional conviction of the presence of a superior reasoning power, which is revealed in the incomprehensible universe, forms my idea of God."

I think that the early American Deists, Thomas Paine, Ethan Allen...Thomas Jefferson (Who swung around a lot of belief systems)...Benjamin Franklin, George Washington...These men represented an age of serious thought and spiritual exploration that hasn't been replicated since. If anything, I think we have regressed as a nation, in terms of using our faculties of reason as a supplement to assist in leveling an inquisitive eye at the institution of religion. That's not to say that I'm anti-church, however; Churches of many religions provide invaluable charitable services to their communities. Could these services be provided by non religious charities? Of course, but these are the institutions that we already have in place, and they have a strong voice in modern political discourse...for good or ill.