Over the years, Warren Buffett has earned his name as one of the best stock pickers ever. But what has been his best investment? His firm, Berkshire Hathaway, has a portfolio consisting of over 45 businesses, ranging from renowned car manufacturers to packaged foods companies. I’ve been scouring his portfolio and I think I’ve cracked it. In my opinion, it’s Coca-Cola (NYSE: KO). Buffett first invested in the stock back in 1988. Today, he owns 400m shares worth over $24.7bn. There are a few reasons it stands out to me. Firstly, it highlights perfectly Buffett’s goal to buy companies with moats that can give it a competitive advantage over many years. Coca-Cola is an iconic brand with huge demand. Every day, more than 1.9bn servings are consumed in over 200 countries. There’s also the income he receives from the investment. Today, Coca-Cola has a 3.1% dividend yield. However, for Buffett, that works out more like 60%. That’s because he’s set to receive $776m in dividends this year from stock, representing a 59.7% yield on his original $1.3bn investment. Finally, with it being Berkshire’s longest continuous holding, it also highlights the power of investing with a long-term outlook. Building wealth doesn’t...