I tried various headphones straight out of the TV and found the SR80s the best as they have the biggest sound stage and greater dynamics. They are also easy to drive, so the TVs headphone amp will cope fine. They did not sound as good as out of a headphone amp and suffere because of the poor sound of the TV. The adverts sounded best of all!
The Grados leak a lot of sound, so will annoy anyone else in the room with you. The Denons are closed backed, but also leak sound. They have a bigger bass emphasis than the Grados (out of an ipod for that comparison).
I have not tried them, but AKG and Sennheiser make specific TV headphones.