Reference Level Recording of Classical on CD's?

Without knowing your preferences it is difficult.

I can list what I like:
I second Newbee's recommendation of Mahler's 1st symphony on Telarc with Benjamin Zander.

I also find Mahler's complete symphonies set with Chailly to be pretty good from both performance and recording quality standpoint.

Also, a must have, in my opinion, is Mahler's 2nd with Bernstein on DG. It is an older recording, but still quiet good and preformance is very good, emotional, typical of Bernstein's Mahler.

Shostakovich Piano Trios 1 and 2

Shostakovich's Quartets with Fitzwilliam String Quartet on Decca.

Shostakovich's 24 Preludes and Fugues with Konstantin Scherbakov on Naxos(although this is a good performance with good sound, I still prefer Tatiana Nikolaeva's recording).

Schoenberg, Silbelius violin concertos with Hilary Hahn on DG.

Rachmaninov Piano Concertos with Ashkenazy, conducted by Previn.

Rachmaninov Symphonies with Ashkenazy.

Shostakovich's 5th symphony with Rostropovich.

Bruckner's 8th symphony with Boulez.

Bach's Cello Suites with Rostropovich. This one is a box set.

Again, without knowing what type of classical music you're looking for, it is just a listing of some of the classical recordings I like.

Hope that helps

Have you heard Schubert's piano works?
If not, you have to!
"Evgeny Kissin & James Levine: The Carnegie Hall Concert" is excellent. You can listen to samples on amazon and see if you like it.

Also, "Brahms: Piano Concerto No. 1; Piano Sonata No. 3; Rhapsodies, Op. 79; Piano Pieces, Opp. 117-119" with Radu Lupu is pretty good. Not a big fan of his version of the Brahms Concerto No.1, but the solo stuff is very good.

Newbee, this is the Lupu recording I have.

I also have Lupu's recordings of Schubert's piano works, which is pretty good in its own way as well. Lupu shines on solo piano.

Toufu, if you like Bach's piano stuff, I encourage you to pick up Shostakovich's 24 Preludes and Fugues that I recommended above. Great price/performance value of it on Naxos's Konstantin Scherbakov recording. Since it's on Naxos label, it is pretty cheap.