Nvidia has been the gold standard for AI investing since the start of the AI megatrend.The topic of the "best" artificial intelligence (AI) stock to buy right now is a spirited debate. One may advocate for companies building AI software, while another may be a proponent of rising stars like AMD (AMD 0.52%) and Broadcom (AVGO +3.02%) after their OpenAI partnership announcement.There's also a case to be made for a microchip manufacturer like Taiwan Semiconductor Manufacturing (TSM +1.14%). However, the gold s ...