List of albums that will still be popular 50 years from now...

Czarivey, it's a long process, it takes time. But I am on my way, I gradually stop listening most of what I have been listening.
In 500 years it is possible that humans will change quite dramatically, perhaps becoming sort of enhanced humanoids or something else, and music as we know it will be irrelevant.
But in the near future Western and Middle Eastern classical music should survive.

Indian classical music too.

Inna,

Nearly 20 years ago, I stopped listening almost every popular title listed here (simply got bored and please DSOM, LZ and RS listeners don't get offended, but it's true) and listen to mostly what's strange, weird, unusual and sophisticated plus indeed classical music. I get far more joy from Michael Rabin than from Michael Jackson for sure!

I'm seller of music for VERY long period of time (since my early teens) and as once Scarface told, I "don't get high out of my own supply" and usually what I sell I can only listen for grading purposes. 

So you are on your way too.
But I will never stop listening to Bitches Brew and Pangaea by Miles and to some McLaughlin's music. Or Camaron's flamenco singing. And I hope all this will still be listened to, at least by some, in 500000 years.
We live forever.

1 Perl Jam album. Which doesn't matter because they all sound the same.