CD, all the way, every day.
It's buried behind a bunch of shit rn but I have a shelf of CDs. I try to own a CD of every album I love that has a CD available. I just this past week ordered the Hawaii: Part II CD that just came out, it is now a part of my collection. I also have a CD of the Rocky Horror Picture Show soundtrack arriving along with the blu-ray in the coming week.
A lot of people seem to miss the fact that CDs hold uncompressed audio, because they simply hail from a time before digital audio compression was possible. I've met several people who seem to think streaming services like Spotify and Apple Music are higher quality than CDs, simply because CDs are old. Most of them won't listen when you tell them those streaming services just take the uncompressed PCM from the CD version and compress it into AAC or Opus.
It's such a joy to be able to substantively support a musician you like while also being able to own their album in a DRM-free, uncompressed, pure form that's almost always the highest quality version of their music you can listen to (unless they have a Hi-Res version available for download on another platform). Also you usually get cool liner notes and cover design, sometimes even bonus tracks that aren't on the streaming versions.
One of my favorite facts of CDs is the same benefit physical media has for movies and shows. Not just being able to listen to artists that aren't on the streaming services, but being able to choose what version you listen to. For older music, in most cases, the only version of an album on streaming is going to be the most recent version. But you'll often find, if you're searching for the version that's closest to the original, with the best fidelity and dynamic range, you'll want the oldest CD release available. See: The Beatles. Google "the loudness wars" sometime, and be extremely wary of "remasters" of older music. They usually just crank the levels and crush everything. One of my favorite albums, Klaatu's Hope, sounds great on the original Justin Records CD, and all subsequent remasters - even the one done by the band themselves - are mixed like shit and brickwalled to hell and back. I love having that original CD and knowing the version of the album I'm listening to is superior to the version on Spotify or Apple Music in every way - in ways you can actually hear.
For most casual listening I use software like Exact Audio Copy to rip the CD to FLAC files I store on my phone. Because yeah, I'll be the first to admit the smartphone is far more convenient than lugging around a CD walkman and a bunch of delicate discs. But if I can, I might grab a disc or two and pop them into my car's stereo, as it generally sounds better than the compressed bluetooth streaming from my phone (I am too lazy to connect an aux and also call functionality is useful).