I love
Mad About Bach, a CD of many diverse Bach pieces for the masses (of which I am one).
It's got piano music, harpsicord, oboe, violin, full orchestra, etc... After that, I branched into more specific pieces. If you like Bach and Piano (I do), anything out of the Glenn Gould collection will do.
The Goldberg Variations are a classic. I like the
English Suites and One and Two Part Inventions (all Bach, all piano).
Think about Opera, specifically Mozart's
The Magic Flute. It's awesome!! Don Giovanni is also great. A good version of
La Boheme is also hard to beat.
To be honest, I've never given Beethoven a chance. More modern guys like Stravinsky and Tchaikovsky are great. It's a wide, wide classical music world out there!