If a spam comment looks to be manually created, I mail the author and offer him a sponsored post. Otherwise, Akismet & Bad Behaviour manage to catch around 95% of spam, so I don’t spend too much time in my moderation queue.
I don’t understand the comment I recently received that was similar to yours (this comment was made by… …) – there was no content to the comment other than that, so unless someone was testing out which blogs would let it through before sending some real spam, it seemed pointless…