Alphabet is firing on all cylinders.Alphabet (GOOGL +0.88%) (GOOG +0.82%) continued to once again prove it's an artificial intelligence (AI) winner with growth accelerating in both its search and cloud computing businesses. While the stock is now up more than 50% on the year, it still looks as if it has plenty of upside potential ahead.Let's take a closer look at the company's Q3 results and prospects and why I think the stock is still a buy. Growth acceleratesGoogle Cloud was once again the star for Alphab ...