When you're not spending your time installing software updates, backing up, clearing your web browser caches, reassigning junk mail, keeping track of your passwords...
And here is some underlined text as well.
Essentially any type of formatting can be done to your posts to make them look as good as you would like them to. Additionally, you can view the full source of a post and edit the HTML if needed :)
The great thing about using the post editor is that you can even upload images directly from the TinyMCE editor window. Checkout the screenshot below:
(Placeholder text-sample post in deveoplment.)