(C'm'on, now, I don't think it really needs an explanation.)

Anyways, I use iTunes for my iPod music of course. I also have Spotify, but I just started using the iHeartRadio app my boss introduced me to at work and I must say I'm liking it so far. The ability to share custom playlists and stations is pretty damn awesome. I spent hours putting together my own playlist that we listened to during our shift last night (I'm 3rd shift) because he happens to have a PA device that he always plays his stuff from on there. I don't know if I'll roll with a monthly subscription over the free Spotify, app, though, we'll see how it goes.

It's a mix of punk, alternative, and metal BTW. 

Just Winamp 2. Used that shit for 20 years and never changed it, because it works perfectly for me.
I have used iTunes in the past, but I don't like it. It always wants to update itself, it's friggin' overloaded for a music player and it constantly wants me to buy some stupid shit. I also tried Groove music and while that one is alright, Winamp is just smaller and faster. So yeah, I'll just continue sticking to Winamp. Some people told me that Foobar is better. Other told me to at least upgrade to Winamp 5. But I don't care. Winamp 2 is perfect. For me at least. =P

On my smartphone, I use whatever the hell the Blackberry music player is called. That is all.

Spotify.

Personally, I hate iTunes and it's overall navigation and layout. Pandora, iHeartRadio, and remember LastFm? I liked those apps for general radio and discovering new music based on my tastes... but I find their audio quality and overall presentation not suited for me. Maybe I just haven't ventured far from Spotify since i first started using it... so I may be jaded as to what the other options offer nowadays.

Winter 2013, I had just moved and my PC was temporarily not connected to a battery backup... so of course lightning strikes and fries my HDD. 15 years of MP3s, FLAC, AAC files all a mess and partially lost. That's when I leapt into Spotify and haven't really looked back. Paying for premium allows me to playback at 320kbps and download my songs and playlists for offline use. It has most everything I listen to, and indie stuff or music that I don't find on there I can upload onto my own Spotify from other sources. It has radio, albeit not as good as Pandora perhaps, but I prefer my own playlists anyways. It's pretty much everything I need it to be.

I have Amazon Prime... which includes music. So it seems rather redundant that I pay for Spotify. Regardless, I still prefer Spotify overall and so I pay for it.

My two cents.

(EDITED FOR WORDING AND GRAMMAR)

Bittorrent

Spotify ( need to pay it soon) and i started to give Pandora a second chance

other than that Youtube but everyone uses that so eh

foobar2000

itunes because of familiarity with it, using it now for the last 15 years or so and really just it's my go to program for putting music on the system.

Never had an apple product to use along with it, but just enjoy the library and ability to merge and cut songs with it as well as change formats has been really helpful for various non music related tasks for me.

That said.. the album rating blue stars rubbish is really annoying me recently and the ability to drag and drop from the music library to a usb device like my phone has been severely limited in the last couple of updates, wondering would it be time for a move to winamp now.

I use three programs,

I use Itunes to play music I own.
I use Spotify to find new music and play songs I do not own.
I use Pandora as a personal radio and use it while driving.

Youtube is also decent to find some music but it is slower than just using Spotify.

VLC, I guess.

I'll use Spotify if they release the Persona 3, 4, and 5 soundtracks outside of Japan.

I have tried a variety of apps, but I mostly just listen to CDs in my car.