Best MP4:
yt-dlp --format "bv*[ext=mp4]+ba[ext=m4a]/b[ext=mp4]" "https://www.youtube.com/watch?v=oHg5SJYRHA0"
Best audio:
yt-dlp --extract-audio --audio-format mp3 --audio-quality 0 "https://www.youtube.com/watch?v=oHg5SJYRHA0"
Playlist:
yt-dlp --yes-playlist --format "bv*[ext=mp4]+ba[ext=m4a]/b[ext=mp4]" "https://www.youtube.com/watch?v=oHg5SJYRHA0"