For this achievement you need to watch 20 shows, this means videos as Demand 5 counts any video as a show (Even Films) so you should get this without any effort whilst going for the other achievements for watching 10 Home and Away episodes, 5 Films, 5 Entertainment shows, Milkshake Shows and 5 Documentaries for
The Watch 5 Films achievement in Demand 5 worth 0 pointsWatch 5 Films on Demand5 to unlock this achievementRemember you snap this app and carry on playing your games or other apps, also in your console's audio settings you can choose which app sound is more prominent if you do not want to hear the films.
Note: Demand 5 is rather buggy and if for any reason a video errors during playback that show will not count, meaning i assume that it has to be watched in one sitting without interruption for the show to count.