Both are good and both sites have its own features.
With blogger it is really easy to preserve your account. You can easily add new pages and new post. It is very simple to switch to different designs using any of the given templates and layouts. No coding is needed. Blogger supports almost all features that a simple blog should have.
If you are coding expert then wordpress is best for you. It removes all the limitations and its open source. And in Word press it is open source and hence offers you fully customization. It offers thousands of themes for almost all niches.
I was recently helping a friend with a blogger problem. They needed to use a separate css file which was needed to style a flash applet. (Blogger seems to only support inline styles.) Try as we might we could find no way of uploading a css file to blogger. I did find one article about uploading the css file to Google drive and referencing it from blogger. In wordpress (self hosted) this would have been very straightforward.
It very much depends on what your requirements are but I prefer to be able to host any files I like and not just the ones Blogger allows.
I have used both and I personally think blogger is really really good but is limited. You can do so much more with Wordpress and I find it easier to manage than blogger. Blogger is sufficient if you are only going to do blogs but if you are planning to expand in the future, wordpress is better.