Look Back Achievement
Watch any episode from a previous season to unlock this achievement.
Currently one of the only shows that provides a previous season is Buffy the Vampire Slayer. So simply go to 'All Shows' then search out Buffy and use the to move to the right to get to the full episodes area. Then select the previous season and choose an old episode from season four. This will also count toward the original drama TV show achievement.
Note: While all of the achievements can be a little bit buggy, this one is by far the most difficult of them all. If the fast-forward trick does not work, I suggest letting an entire episode play, snapped or not, and then seeing if it updates. This has been reported to work in cases where people were not able to get it simply by fast-forwarding and watching the last minute or so.