Beethoven- Violin Concerto (especially Larghetto section) & Symphony No. 7, Allegretto.
Mozart- Concerto for Flute & Harp, Andantino (in what I consider the most beautiful melody I ever heard)
Bach- Suite No.3 in D Major, Air & Jesu, Joy of Man's Desiring( when in the mood for uplifiting choir/cathederal tune + include Mozart's Mass in C Minor too)
I do hope you will enjoy these sampling of great music. I'm 35yrs old & rocked to the Stones to Lincoln Park, Gaye to R. Kelly, but classical music can be quite an enjoyable listen. There's a reason this music created hundreds of years ago still resonate today.