Your question, "What is the best Wordpress theme for my blog" is nearly impossible to answer. There are an incredible number of factors that go into website design to influence conversion, sales, and user experience.

A theme out of the box probably isn't the "right" answer for long-term success, but it may get you up and running. I don't think website design is ever "done". Think of megasites like Amazon or Facebook, they are constantly changing an testing.

That said, to set yourself up for growth, the ability to A/B test, change details and layouts, etc, I recommend a custom theme builder similar to Divi by Elegant Themes (www.shaunnestor.com/recommends/elegantthemes)

They have a number of pre-built layouts that you can use as a foundation, but changes as your needs fluctuate.

All the best,
-Shaun