Or you could use the search function...
For the guards, I would recommend http://www.tesnexus.com/downloads/file.php?id=5977.
Also, try searching for some of Duke Patrick's mods, they affect AI.
I haven't used this, but http://www.tesnexus.com/downloads/file.php?id=8273 expands upon the combat and NPCs are effected by the changes (i.e. they'll attack and defend in new ways).
I'm sure there's more AI improving mods out there, all you need to do is search for them.
Edit: ninja'd on the Deadly Reflex mention.. :toughninja: