As good as bloggers like comment on their post, it is also good to fight against spammers. Digg into ways you can get your blogs prevented from Spam Comments.

Choose a Good Comment System: There are various comment systems like Disqus, CommentLuv, Akismet, Facebook Comment, Google+ Comment. All this are good but if not properly consider, you audience will be fed up of visiting your blog or commenting. So you must choose a very good comment platform

Moderate all Comment: After choosing a good comment system, it is advisable to change your settings to approve comment before posted. This is a good way to see spam comments or valid comments

Limit the Number of Links: Spammers usually include large number of links into their comments, so it is better to limit the number of links allowed in comments. You can change this via discussion settings tab of your blog.

Close Comments after a Specific time Interval:Comments on older posts have higher chances of being spam than new posts. You can do this by navigating to the settings of your WordPress blog and then choose the Option of “Automatically close comment on articles older than y days” where y is the number of days after which you want to disable comments on your blog

Don’t Allow Comments on Pages: Top-level pages usually have high page rank, so the comment spammers often attack those pages first. To prevent them from doing so, you can simply turn off comments on pages.

Install GASP Plugin: The Growmap Anti Spambot (GASP) plugin adds a small check box asking people whether they are human or not. This does not cause any problem for consistent visitors.

Read >> http://www.techracle.com/ways-kick-spam-comments/

Remember to comment on this thread so we can learn from you.....

The smartest way is simply to install and activate the ASKISMET PLUGIN.

Yh, u re right bizfirst and some other plugins like disqus is great but there are some tins to even understand after activating those plugins...