Even though everyone loves to hate it now, I’m gonna say…iTunes. Around 2004 I was fed up with the hideousness of MusicMatch Jukebox and WinAmp, downloaded iTunes for Windows, & was so impressed by the clean and elegant UI. Within a year I’d bought my first iMac—a computer that wouldn’t look awful in my small studio apartment—hooked it up to my stereo and ran it usually with the visualiser in full screen l. I ripped my whole CD collection and eventually moved everything to the Mac.