Trashman, Andy Capp, Flunky, A Day In The Life
are quite funny games in their own right - heck , in the last one, you even get to play as Uncle Clive himself!
On the other hand, I never watched East Enders
(it was never broadcast down here), but if it was as bad as the game, then it would not have been exactly an uplifting experience, I think.
That said, I wouldn't want to enter "shameless plug" mode, honest, but I believe the most depressing Spectrum game ever is that short text adventure I created for the CSSCGC 2015, The Trunk,
based on Dalton Trumbo's Johnny Got His Gun
movie. What I put at the beginning explains it all: This game is bleak, painful and unpleasant - just like war itself. Don't say you weren't warned.
You take the role of a hospitalized American WWI soldier who, after having been hit by artillery fire, lost his limbs and is blind, deaf and dumb, and so heavily sedated that he suffers from religious-themed hallucinations (there is a short cutscene in the middle of the game reflecting this).
I put some touches of black humor here and there (e.g. the doctors' dialogue at the beginning), but I think the final result is altogether very sad and depressing. Again, just like war itself.
The game does not end, or better said, it freezes when you are finally aware that no one will put you out of your misery and you will spend the rest of your life lying in a hospital bed as a human trunk, hence the title.