There are some plugins for Movable Type that should just be considered a requirement to any new or existing MT setup. I've christened this list of such plugins The Essential Movable Type Plugins List. There are lots of good plugins, but only a few that should be installed no matter what. I hope to capture that core set and keep adding to the list as new plugins are released.

Moderate Via Delay - Revives the MT-Blacklist functionality to moderate or junk comments and trackbacks on older entries. This fills a major gap in the Spam Lookup plugin as a replacement for MT-Blacklist.

NaughtyWordChars - A plugin that strips malformed characters out of posts and comments pasted in from Microsoft Word documents. There's even an option to run it on previously published entries.

E-Mail Blacklister - Sometimes all the Spam blocking in the world won't stop a persistent spammer, but often that same IP hopping spammer will use the same e-mail address in every comment. Enter the low tech E-Mail Blacklister. You might not ever need to use it, but when you do you'll be glad it's around.

Certainly there are more entries for this list, but it's a start.