I don't particularly like to log in to WordPress to write a blog post unless I have to. I'd much rather use an application installed on my machine.
On my Mac, I've been using MacJournal for quite some time. It's a really good tool and is suitable for anything from a quick 50-word post to a 2,000-word manifesto. I've barely scratched the surface of what this tool can do, but so far, I'm very happy with what I see.
Photo credit: Mariner Software