In short, while Microsoft and Nvidia are close contenders, Amazon is the best artificial intelligence (AI) stock in the S&P 500 to buy now, if "best" is defined as the stock with the highest net percentage of buy ratings. Here's what investors should know.

Both of those AI bellwether stocks are still reliable long-term investments, but investors shouldn't gloss over the less obvious AI plays that might soar higher over the next few years. Let's take a closer look at three of those companies: Oracle (NYSE: ORCL), Broadcom (NASDAQ: AVGO), and Arm Holdings (NASDAQ: ARM).

Microsoft and Oracle are top cloud computing stocks that benefit from the proliferation of AI services in the cloud. Microsoft is growing faster than Oracle right now. At the same time, Oracle's solid revenue pipeline is why its pace of growth is expected to top Microsoft's in the future.