Most of us have I think seen The Twilight Zone, and most if not all will agree it was incredible television. What are your favourite episodes? Spoiler alert: the series (the original anyway) is over fifty years old now, so if you haven't seen it do yourself a favour: plotlines may be revealed here so don't complain you ain't seen it yet.
Dead Run: From the 80s revival. A down-at-heel truck driver finds unexpected work ferrying souls to Hell, but should they all be going there?
To See the Invisible Man: A superb one, again from the 80s series, in which a future punishment is being marked with a symbol which ostracises you from society. Nobody will talk to, interact with, or even acknowledge your existence.
Five Characters in Search of an Exit: Incredible revelation at the end when you realise who and what the five characters actually are (60s series)
Time Enough at Last: A fussy man who never has time to read the books he wants to gets his wish when the world is destroyed and he is the only survivor. But as usual, there's a twist in the tale ... (60s series)
The Hitch-Hiker: A woman is terrorised by an unknown man who keeps appearing on the side of the road thumbing a lift. When she phones home in panic, she realises the awful truth... (60s series)
The Monsters are Due on Maple Street: A microcosm of how easily paranoia runs riot, with tragic circumstances, though the ending is a bit silly. (60s series)
I'm sure there are tons more, though this are the ones that spring most quickly to mind.