I saw this when it originally aired at age 18. I remember it being creepy and made me doubt myself.
On second viewing I found it to still be a good watch. If you take into context of when it aired and who was "presenting" the show there are many clever elements. I grew up watching Sarah Green on Blue Peter, Mike Smith was her long time partner and they were newly married at the time, so this was a nice touch. Michael Parkinson, or "Parky" as he's affectionately known, was a national treasure before the term was coined. Craig Charles was that cheeky bloke from Red Dwarf who first appeared on telly reciting poetry. Overall a heady mix of believability.