your suggestions on a plug-in please

My site has been linked from some aggregators and is picking up some traffic. Along with that come the spammers.

I have Akismet installed to catch comment spam, and it works well, but what I am looking for is something that catches registration spam.

I can’t find a place in WordPress to blacklist actual email addresses or domains (and I want to do it within WordPress). All I can do is edit and delete them.

So, your suggestions for a plug-in that takes care of this? A plug-in that, hopefully, checks a spambot blacklist and automatically marks as a spammer?

I searched plug-ins and there seem to be a mass of anti-spam ones, but I figure input from people who’ve used them would be best.

Thanks in advance.