Hello,
I recently bought a Tool Shop brand pin moisture meter at Menards. The subfloor and hardwood are both measuring 0% moisture. This doesn't seem right. Any thoughts?

Wood will always have a moisture content, unless it was oven dried.
Did the meter come with operating instructions?

no specific directions. I thought it seemed weird...maybe the pins weren't driven in enough

Which brand provide a good moisture meter reading? As, I have bought a cheap meter but it is not properly working. Please suggest me some good tools.

I use Lignomat. Made in Portland OR. I have used the one sold at Harbor Freight, too.

Wagner for the best, most expensive, but most accurate meters; I use these for inspection reports and warranty work

I also have a General Tools meter I use daily for checking RH and pinless MC. That only cost me about 120CAD and is worth every penny.

Some meters only read down to 3%. So you could get zero if it's lower.