These may not be the best known works of classical music, but they're each incredible works, and if the least they do is make you want to hear more classical music, then they've done their job.
These two albums are cornerstones of my collection:
Muti/PO: Symphonies 1-3, Poem of ecstasy, P. of fire - PoE and Symph1 (esp. mvmt 6) are two of my favorite pieces. no other recording of PoE keeps the second half as tense nor does the coda as perfectly as this one.
Lettberg: Solo piano works - I have to highlight her op. 18 and op. 4, two large piano works that mostly predate the sonatas. Great great romantic, virtuosic passionate pieces that lie somewhere between Brahms more violent intermezzos (eg, 76/1) and Chopin ballades. The rest is all quality.
Others to supplement, that I don't feel as strongly about.
Ashkenazy: Piano sonatas - older recordings, but he captures the more eccentric side so essential to Scriabin, like the frenetic no. 2 and the disturbing no. 9. I still think Ashkenazy is more at home with Rach (ossia pc3!!) though.
Diev: Preludes - simply a great value, for the 48 short pieces you get here. Solid playing, I don't think he has quite the edge needed to pull off the more hairy pieces, but he nails the tender side of 11/11 and 16/3.
Get these recordings.
These may not be the best known works of classical music, but they're each incredible works, and if the least they do is make you want to hear more classical music, then they've done their job.
These two albums are cornerstones of my collection:
Others to supplement, that I don't feel as strongly about.
Oh god OP, that Kleiber beethoven 5 is crazy intense. Good choice.
Mahler's Symphony No. 5 - Bernstein
Mahler's Symphony No. 8 "Symphony of a thousand" - Sinopoli The greatest recording of this ever. And yes I have heard Solti and Horenstien.
Schumann's Fantasie in C major If you know Richter's Schumann, no explanation is required. If not, you need to hear this.
Scriabin's 10 Piano Sonatas - Ashkenazy I've heard people call Ashkenazy bland. He definitely isn't here.
I really don't want to limit my choices, but I think maybe I should keep it at 5 or this list will become too big..so for something completely different..Phases - Box set of Steve Reich's music on Nonesuch label