Insanity is your friend.
It works on most creatures, although not on those pesky weeds.
Most of the time, when you drive a creature insane, it's too goofy to even attack you for the duration. It's one of the reasons why my Bard is my best buddy. [img]tongue.gif[/img] My Bard has used Siren's Wail throughout the game with great success.
I think my combat strategy pretty much boils down to buffing & driving them nuts, and then closing in for some leisurely hack 'n slash.
It's almost unfair how well it works throughout the game - especially on those critters with lots of hitpoints.