Before you pick a theme
What is the goal of your website. Don't pick a theme named Cupcake Shop Theme because you have a cupcake shop. The truth is that you can use any theme to achieve your end goal. That's why some people transform from Blogger to developer.
I use bootstrap based themes mostly. I like that they are built mobile first.
Right now on my website, I'm using a parent/child theme called ContentBerg. It has the post format's I was looking for and madde it really easy to switch.