Not even a discussion! A free google service or an open source application stored on your own web server? Wordpress wins this one any day out of the week. You could argue the user interfaces between the two. But the fact that one is open source makes it far better than the other.
Great ! ! ! currently I use WordPress, its easy to modify and make changes for the content. You can put some widgets. You can choose templates from wordpress.org.Its code at Theme Editor also easy to understand. You can place some open source code for the page.
I don't really use others bloggers anymore now that I have my own domain & hosting. Though, as I recall from when i did, Blogspot seemed to work better for me than wordpress did. Easier to navigate for me anyways.