"Mad Man" Don Draper's Go-to Cocktail

Like a lot of my friends, I've gotten pretty fond of mixed drinks over the past few years -- both the latest creations of talented "mixologists" and classic libations such as Manhattans and Bloody Marys.
One cocktail that's gotten a whole lot of attention in recent months is the Old Fashioned, thanks probably in no small part because it's the drink of choice for the suave but caddish lead character of the TV series, "Mad Men."
In the New York Times' Dining section 3/21/12, there's a feature about the current popularity of this drink, the variations (some over the top and frowned upon by serious bartenders) on it, and some ideas about how to make a good one. Click here to read the piece.
I find it a difficult drink to make. A few months ago, I started searching online for some info about the Old Fashioned and how it different from a Manhattan. It was hard to find anything definitive, and the Times article helps to explain why that is. The Times does not include a recipe, in fact.
It does link to a site that has a nice, step-by-step instruction about how to make an authentic (or so the site claims) version. Click here to check that out. Pretty simple: bourbon or rye, sugar and bitters -- with or without ice, and add a little water if the drink seems too strong.