Justin bieber's old songs. Well I was so trashed out when I said I liked his music a few years ago that I haven't said anything since 3-4 years ago. Even my best friend, whom I've know since 3 years, doesn't know about that x) 
but it's one of the only music that really has immediately an effect on me. For lots of others, I need to be a little prepared to really have THAT FEELINGS haha

90s Euro dancepop or Rave

Early 2000s pop like Britney Spears or Christina Aguilera 

Some of Nu Metal songs or grindcore bands with vulgar lyrics like Carcass and Cannibal Corpse .___.

And a bit of kpop c: (when i miss my college years)

well this might sound very weird but sad songs make me happy. so,when i'm sad i listen to sad songs which makes me happy. 

like:

https://youtu.be/DbPsIWto5PY  - mr.samdman

https://youtu.be/5m2XqQQ7jrE   - if by chance 

https://youtu.be/-tJ0ckX8-WQ    - in this shirt

https://youtu.be/s9TOeyLJ97o   - into your arms (melody- without rap)

https://youtu.be/50VNCymT-Cs  - let me down slowly 

these are just the few of those.

I don't really have guilty pleasures I'm proud of all the music I listen to. 

Some cheesy 90s eurodance and early 2000s pop songs. Good times.

Some Brazilian funk songs. The vibe they give off is good but the lyrics.. are bad, no joking.