You should use the verb *favourite* and not *favour*. [*Favour*][1] means *show an approval or preference for*, while [*favourite*][2] means *record to enable quick access*. It is true that you favourite a video on a website if you like it, but the sense you want to convey here is not that you like the video but that you mark the video in some way. Of course, the past tense of *favourite* is *favourited*.


  [1]: http://oxforddictionaries.com/definition/english/favour
  [2]: http://oxforddictionaries.com/definition/english/favourite