Below is the favicon graph of the top 1 million sites of the world according to the Alexa ranks. The bigger the favicon, the higher the Alexa rank it represents. That is why, Google is having the biggest favicon in this chart.

Favicon Graph of Top 1 Million Websites

If you can't find your blog in this favicon image then you can search your blog's favicon by visting the link http://nmap.org/favicon/ if its Alexa ranking is in 1 million. Only problem is that if you are using the Blogspot blog and using your custom favicon then still it will show the Blogspot's favicon.
 
Top