It depends what you want to do with it. Wordpress's policy prohibit advertizements on their blogs, however Blogger does not. This is of course for the free use of Wordpress. I have never used any of their upgraded features, as my Wordpress blog is just for personal use. To me it seems that anything you want to do extra with Wordpress you have to pay for it. With Blogger you get a lot more for free, including free linking to your own domain and the ability to have ads.
In all honesty, I've slowly been porting my whole like to Google. You know how you have the Apple lovers? Well I'm a Google lover so if I can get it through google I tend to do that.