I think there is a difference when an actor just takes bad roles and when they can't act. For instance, I've seen Tom Cruise in pretty lame roles, but given a good script, like Magnolia, he was very impressive.
There's a Italian movie that Penelope Cruz was in called "Non ti Muovere" (Don't Touch) that really gave her the opportunity to show what she can do -- it hasn't been released in the US yet, but you should check it out when it is.
Brad Pitt and Ben Afleck pick such bad scripts that it's really hard to tell with them. I am always irked when an actor won't move out of his or her comfort zones.
There's a Italian movie that Penelope Cruz was in called "Non ti Muovere" (Don't Touch) that really gave her the opportunity to show what she can do -- it hasn't been released in the US yet, but you should check it out when it is.
Brad Pitt and Ben Afleck pick such bad scripts that it's really hard to tell with them. I am always irked when an actor won't move out of his or her comfort zones.