The title says it all.
My 56* Vokey is a close second, but nothing can top the flat stick. I've got a small stable of Newports in different finishes, and I just picked up a Gun Blue Circa 62 No.3. I'll usually putt around on the carpet the night before a round and pick my putter that way. I also take course conditions and weather into account.
So how about you, what's the crown jewel of your bag?