When accusing domain owners of spam, don't forget that anyone can spam thousands of blog comments for $5 using any domain (think negative seo). For example, I really doubt that Steve Pavlina (#3 in the spam domains list) would spam his own domain. Most probably some competitor wants to take his domain out of the google index.
<p><pre><code> Those were the top domains used by spammers:
16514 gmail.com
7300 hotmail.com
3267 yahoo.com
</code></pre>
How come gmail is so popular with spammers?