Here's all I could come up with:
-Get a bunch of dvds of live concerts of artists you dig. Have a giant marathon with yourself and get snacks too. Sing along.
-a huge mp3 player to hold every song you've ever wanted and bring it with you at all times.
-Do you play instruments? Have you ever wanted to? Buy yourself a decent beginners guitar for christmas you can get an electric guitar with amp for a reasonable price (under 250 bucks)...that's always an awesome gift.
-If you already have an instrument, get a bunch of goodies like replacement strings, reeds, picks, cords, drumsticks ...whatever goes with your instrument
-Install a new car stereo or get speakers or subs for your car.
-a computer/gaming chair with speakers built into it for ultimate lounging and relaxing
-A karaoke machine, who doesn't love to sing loudly in their living room? (if that's too much a hassle they have singing games for gaming consoles like wii and playstation. You could also try the 'rock band' or 'guitar hero' games)
-Invest in some *really* nice headphones, nothing beats listening to music with headphones, makes for a much more awesome experience!
-Other stuff: posters of artists you like, band tshirts, box sets, biographies on your favorite musicians.
-If you dig vintage then get your hands on a record player and a few records. (they have record meets mp3 players and portable turntables now!!)
-A new cd changer with equalizer
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