Robert Horry ... and that's because he's done it constantly and for many teams. In fact, his reputation is that of that clutch 3 pt shooter for the finals, whether it's Houston, LA, or the Spurs. All and all, it's a great epithet to have since you really don't have to do much for the remainder of the series to get the accolades.
Think about it, all of Horry's shots from Olajawon were from double or even triple teams on the big fellow. How's that for being wide open and fortuitous at once? That's how the reputation got started. At least John Starks needed to blow past someone to get off a clean look. And with other great big men like Shaq or Duncan around, he could reproduce the same effect in latter series.