It isn't easy for a huge company to grow, but if any can continue to do so, it's this one.No, it's not your imagination. Stocks are expensive these days. Factors such as the continued rise in the U.S. economy, thin interest rates, and the ease of owning equities have driven the market ever skyward, for the most part.So it pays to be choosy, and it especially pays to select only the finest stocks that can stand the test of time. One of these beauties, in my opinion, is Walmart (WMT 0.45%). Read on for my No. ...