Have you ever played batman ( which mordors combat is based on) it has depth of gameplay, attack, block, roll and counter attack. It's actually an excellent action combat system IMO.
I like what I've played of Arkham Asylum but not because of the combat. It's pretty smooth, and it has a nice flow to it, but I dislike how cluttered the UI is. I especially don't care for the way it shows an icon above the enemies every time they're about to strike at you.