Since I started blogging back in 2009, I have used WordPress. There are/were other blogging platforms, but WordPress is the one for me.
WordPress is one of the easiest and most popular blogging platforms to use.
I have all of my sites hosted on WordPress. Including this one.
In December 2015, I was able to speak briefly with WordPress Founder Matt Mullenweg during Wordcamp. He is a nice guy and has a brilliant business model for Automattic. You can learn more about Automattic by listening to a great interview with Matt by Tim Ferriss.