I would take the Lakers' defense over the Nuggets because they have better individual defenders (Kobe, Ariza, Bynum) than the Nuggets (Camby and no one else).
That's another great point. The Lakers have numerous players in the rotation that play very good defense... Kwame, Bynum, Kobe, Ariza, and Turiaf. Hell, Farmar's defense is solid too. We can easily put a great defensive lineup on the floor and the Nuggets really can't.