10. The House Of The Time Lords (Doctor Who/House)
Kicking off our countdown of fan made Doctor Who crossovers is this awesome video in which the Tenth Doctor meets one of his own (sort of!) as he comes face to face with Hugh Laurie as Dr. Gregory House. As the Head of Department of Diagnostic Medicine, Dr. House would have a field day if the world's favourite Time Lord was ever admitted as one of his patients and this tantalising trailer - edited in the style of Doctor Who's 'next time' previews using clips of David Tennant's first episode, The Christmas Invasion - gives hopeful fans an insight into what such an encounter between two of TV's most famous doctors would entail. Just imagine these two in a room together. Has the Doctor finally met his match (and vice versa?)