One atom is one of my favourites, but I am an all time Monokai lover. I am currently using One Monokai pro.

I love the dark theme of White from Arthur White. I only do a couple of tweaks to add a little more contrast:

{
    "editor.tokenColorCustomizations": {
        "[White]": {
            "comments": "#6b7a88"
        },
        "[White Night]": {
            "comments": "#a8a8b1"
        }
    },
    "workbench.colorCustomizations": {
        "[White]": {
            "tab.inactiveForeground": "#6b7a88",
            "sideBarTitle.foreground": "#6b7a88"
        },
        "[White Night]": {
            "tab.inactiveForeground": "#a8a8b1",
            "sideBarTitle.foreground": "#a8a8b1",
            "editorLineNumber.activeForeground": "#a8a8b1",
            "editorLineNumber.foreground": "#747481"
        }
    }
}

Give a try to Soft Colors theme.

After using dark themes for 4 years, I've recently switched to GitHub Light for a change. It's been good so far but if I have to choose between dark themes, I'll choose between Atom One Dark, Monokai Pro and SynthWave '84 🙂

I flip between Night Owl, Dracula, and SynthWave '84. I haven't figured out what one is my exact favorite, but I am leaning towards SynthWave.

I do not use the glow effect when Synthwave

Night Owl is supposed to be for nighttime coding but I feel like the blue is too harsh.

SynthWave '84 is my absolute favorite!

You can try Palenight Theme by Olaolu Olawuyi, very cool

Nice, Night Owl was my favourite 🦉, recently switched to Dracula 🧛‍♂️