I use open office for OSX for hubpages. When, I'm writing outside of hubpages, like for writing for my website, I use Textedit (which is way better for HTML).
I actually keep an open document at all time, keeping items I put in each post (like mailing lists code, etc.) and then build that way.
Writing on Hubpages or through other blogging software is incredible annoying. I paste everything in and then work out format within each respective program.