After penguin, I think blogger is more easily handled onpage seo and get page 1 on google. It's much easier than wp...
They are both PR9 sites and therefore have similar power with Google when writing any blog articles using either of them. Mark
I would say WordPress. If you carefully watch the content of blogger you can eaisly notice that there is lots of spam and content without any quality. But WordPress have more quality content and have very less spam then blogger. Because of this WP contain rich quality contain which help in SEO. So WP is better then Blogger.
That has nothing to do with the website itself, but the individual who's behind the blog and the type of content.