Gold investing options?

Hi there,

What's the best way to invest in gold? I know a few ways like ETFs, ETRs, and obviously the physical gold. But any idea what's the best option?

Also, any popular choices in each of the option? For e.g., MNT is an ETR. But then it has a 0.35% expense ratio. Plus there are several other fees if you ever want to redeem it for physical gold.