There was a time when tobacco stocks were among the best investments you could own. For example, Altria (MO -0.27%), which for much of its history also owned what is now Philip Morris (PM -0.93%), was the best-performing stock on the market over a nearly 50-year period, according to Wharton professor Jeremy Siegel. However, over the last decade, that's changed. Shares of tobacco companies like those two and British American Tobacco (BTI 0.41%) have succumbed to pressure from declining cigarette sales, an in ...