I am a fan of plugin WyPiekacz available at http://wordpress.org/extend/plugins/wypiekacz/ for its capabilities and suggest feature list of this plugin for integration with anti splog to fight spam in a better way. Quoting some of the feature related to fighting spam.
You can also enable options to enforce following rules:
maximum link count - extra links over limit will be removed;
position of links - links inserted too close to the beginning will be removed;
maximum title length - too long titles will be truncated;
maximum category count - extra categories will be removed (if you do not allow to use the default category, WyPiekacz will try to remove it first);
maximum tag count - extra tags will be removed;
If you have to deal with lots of post submissions (especially automated ones), you can enable following helpful options:
do not save post at all (use this option with caution - it can negatively affect user experience. Therefore I recommend to enable it if you have to deal with lots of automated spam only);
automatically move abandoned Post Drafts to Trash (or delete if Trash is disabled) after given number of days. You can also decide to force deletion without moving to Trash;
automatically lock or disable user account after he/she will abandon given number of drafts (this function requires the User Locker plugin);
Except for first paragraph, rest of above content is from wordpress plugin page.