Spam is shit. Everyone knows that.
Setup Spam Karma 2 (Dave has written an in-depth tutorial about installing SK2) and it is pretty simple to work with. One of the major drawbacks that I find in Spam Karma is that you cannot moderate comments. So install SK2 Moderate Plugin which can be downloaded here. You need to upload the ‘sk2_pjw_moderate_plugin.php’ file to ‘wp-admin/plugins/SK2/’ Once that is done go to SK2 admin panel (from your WordPress dashboard) and set ‘Moderate’ to Enabled. (See screenshot)
This will make sure you will need to approve every comment before it appears on the blog/site. Make sure that you set “Captcha Check” to Disabled. In certain cases however, inspite of all this being done a few comments might slip through and appear on the blog without your approval. To avoid that go to ‘show advanced settings’ and in Anubis, play around with values (see screenshot) until it matches your site. Be careful while doing this.
There you go. This is best spam fighting combination I have managed to configure and works neat as well. The value in Anubis plugin is the key thing that makes sure the comments will be moderated before being displayed. Thought of writing a post about this because I couldn’t find many posts on how to do it anywhere. 
Keep smiling and stay hungry!