- Bandcamp (pay-what-you-want)
- Qobuz (high quality downloads, the CD quality option is the cheapest but it's really also plenty good enough)
- HDTracks (pricier than the cheapest option on Qobuz but better quality)
- 7digital (offers cheap mp3 downloads but some albums might be pricier than Qobuz and lower quality)
- iTunes (the app, on Windows Store, cheapest of all and lowest quality but cheap but also better quality than free streaming plans)
- Used CDs which you can rip to your computer and then give away (since you already have the music on your computer and/or back-ups. You'll need to invest in a CD drive, though. And some other media like a hard drive to back up the music.)
Or just use an adblocker like uBlock and listen to Deezer and Spotify on their web apps (no interrupting ads).