I'm currently using BB & SK2 as anti-spam plugins. I don't know much about akismet (I've looked at the codex) to say whether or not it would add to my protection.
If there's a link in the forum to a thread which covers this ground, pls. let me know.
Otherwise, I wonder what folks think about these plugins? The 2 I now have are doing a pretty decent job. BUt I always believe in upgrading to something that might work more efficiently (if akismet does that). I'd like to hear what folks think of Akismet compared to the others