Sleaze: Anything by My Life With the Thrill Kill Kult

Depressing: Roads by Portishead

What is an example of a sleaze song? Not familiar with that as a category of music.

My depressing song is You are my sunshine

For humor, strokin' by Clarence Carter. I've been known to say "ima put on some mood music", then start that track and do a bump n grind to it. Surprisingly, it works often enough that I keep doing it.

More seriously, I favor Barry White for background music for sex. The combination of solid rhythms and that sweet baritone get the job done when a partner doesn't have their own preference, but wants music.

That being said, Prince, during his symbol era, put out a song called 7. It's not even a sexy song, per se. But the rolling rhythm and vaguely romantic lyrics work for me, and tend to work well for others, so it's high on my list of songs for sex. As a single favorite, it takes the spot. https://youtu.be/9V-vcXOpG9g

Depressing though? I am not depressed by music, even sad music. Sad music may make me somber, but not sad.

However, if I need a good cry, the Dixie Chicks version of Travelin Soldier will do it damn near every time. Don't even know why really, but I think it's the voice tone and arrangement that push it into tear jerking rather than the lyrics, even though the lyrics are sad. That's because there's other versions, including by the original songwriter, that don't make me cry at all. No other song comes close to the reliability of tears that one does.

Wax - Scumbag

Wax is a rapper of YouTube fame from Montana (moved to LA), and this is honestly one of my favorite songs. Just about being a selfish piece of shit.

If by sleaze you mean sex, as others have answered, go with Yofukashino Uta by Creepy Nuts. Japanese rap. Look up the video on YouTube and enable subtitles if you don’t understand Japanese. It’s a funny video, but it’ll also tell you exactly what he’s saying (they translate the title as Stayin’ Up Lullaby, but it’s also known as Call of the Night, as in the manga it inspired and its anime adaptation).

As far as depressing… I’m gonna go with Shirushi by LiSA because it’s the ending theme to the saddest anime I’ve seen — the last arc in season 2 of Sword Art Online. I don’t know what she’s saying but it sounds like it fits. See also any of the openings or endings from Your Lie in April, especially if you know what they’re about.

…because everyone else is just gonna post western music.

Curve - Forgotten Sanity

Actually a lot of Curve's catalog probably fits the bill one way or another, but this is the first one that comes to mind.