This will probably turn into a "my list is more obscure/seminal than yours" contest. Mine is fairly mainstream except one

The Stone Roses - The Stone Roses
Pink Floyd - Wish You Were Here
Furniture - The Wrong People
Green Day - American Idiot
Nirvana - Nevermind*
*I'm going to admit I haven't listened to it for years but it is certainly a "must listen".
I'm afraid all current music is ruined for me by autotune, whatever other merits it may have. Whiny attenuated vocals actually hurt my ears.