I played both thoroughly.
Dragon Age : Lots of lore, amazing combat / skilling system, phenomenal graphics and effects. (80-120 hours for one playthrough, excessively good replayability)
Shadow of Mordor : Unparalleled fighting, decent skilling system, wicked graphics, decent (yet short) story. (30-45 hours for one playthrough, pretty much no replayability)
Therefore, I would tend to recommend Dragon Age, even though they are both awesome games.