The Best Framework to build WP Themes?

Which framework is the best?

Best for what?
What features do you need?
Are you willing to pay for one?

Your question is useless in its current form

This is opinion based question so unfortunately there’s going to be no real answer.

You’re going to simply want to find a framework that is well-documented and has a great community to support it.

Personally I use Genesis

I just want to know which one is coded well, easy to use, has a lot of features. I would use it to build templates or websites. I need something to start with that is why I need information. Or is it better to use some themes? Like responsive theme, free theme for wordpress? Or maybe this:

Im just looking for best option.