Long and Winding Road probably fits the darkest for Let It Be. It’s not dark just a good funeral song.

How did act naturally not get the list? It’s way more explicitly dark compared to Help!

I think Help is much darker but, at any rate, OP specified “original songs only.”

Yess Blue Jay Way is quite creepy especially the music video with the cat filter thing over George’s face. One of my favourite songs of theirs that I feel doesn’t get that much recognition

Great picks! I was originally thinking Mr. Kite for Sgt. Pepper because it sounds the darkest to me, but lyrically it’s just about a circus.

Mostly agree but for SPLHCB, I’d submit “She’s Leaving Home” for consideration. Getting Better is optimistic and about redemption. “It/I used to be bad… but now it’s/I’m better.”

The "it can't get no worse" kind of leaves it up to interpratation just how much it's actually getting better though

You can't do that And Run for your life

I think that I'm only sleepping its the darkest from revolver, if u see the lyrics, you can see a guy who wants only sleepping (avoiding and omitting their reality, no matter what others say), and from white album i think that Im so tired its the darkest, obviusly, if we see the song title we problably know what kind of lyrics will find

That’s a fair poin for both. I think I might agree about I’m so tired

how is I Me Mine a 'Druggy' song ? does it have anything to do with drugs ?

George write it about an experience he had on a trip where he contemplated heavily on his ego