Wow. Send me a 500 gig hard drive and I'll fill it for you with new music and new performances of old favorites that will blow your doors off. Here are five recommendations to get you started.
(1) The ongoing Royal Liverpool Philharmonic/Petrenko Shostakovich symphony cycle. You can really start anywhere, but my personal favorite is number 11.
(2) Adams is at the top of his game. There's no recording yet of "The Passion According to the Other Mary," the choral work that the LA Phil and LA Master Chorale premiered last year (I caught the Sunday afternoon performance and was amazed), but there is a solid live recording of "City Noir" from Dudamel's first night as music director of the LA Phil, and a great recording of "Son of Chamber Symphony" with the composer leading the International Contemporary Ensemble.
(3) Thomas Ades is another contemporary composer who keeps hitting home runs. Start with the premiere recording of his Violin Concerto, with Anthony Marwood as soloist and the composer leading the Chamber Orchestra of Europe. Then try his opera "The Tempest."
(4) I don't know of a complete set of Beethoven piano sonatas that is as consistently good as Paul Lewis.'
(5) The BBC Symphony under Edward Gardner have been on a roll with 20th Century Polish composers. The three volumes of Lutoslawski were consistently excellent, and the first volume of Szymanowski is every bit as good. Great sounding recordings, too; the hi-res downloads (available at theclassicalstore.net) are fabulous.
Enjoy!