Classical music newbie needs your suggestions

I had a college friend share his appreciation of classical music with me. Since it sounds you’re beyond that, I’d now say to find a copy of Ted Libby’s NPR Guide to Building a Classical CD Collection. (Ignore the “CD” part of the title.) The greats are the greats, and Libby is informed as well as accessible. Opera, too. Just organize your collection in your favorite manner (I use composer’s birthdate, which gives you a visual timeline of eras) and read the liner notes and Libby’s commentary as you listen. 

I was a rock n' roll kid- Bob Seger and Uncle Ted Nugent. The first classical tune that caught my ear was Pachelbel's Cannon in D. I was 18 yrs. old then. Mozart came next and as a student of music (piano and trumpet) I began to slowly mature into more and more complex classical music. At 60 years old I find my greatest joy listening to the old masters- Handel, Bach, Mozart and Beethoven. I prefer the composers that tried to emulate God by composing purer, higher, nobler music.  I also like French vanilla ice cream and hate butter pecan so there's that. 

Schubert’s C major string quintet may well be the most powerful, absorbing, ..., piece of chamber music ever published.  It is tops on my desert island list.

I admire your quest. This forum may be a bit overwhelming, as most people are listing their personal favorites which you may or may not connect with. 
 As somebody has suggested, you might take a Music 101 or adult education music class to get you started. A good teacher will inspire you with his or her enthusiasm, and guide you on a path of well known classics that have connected to many beginners.

@thomas_vick 

Funny you should such disparate pianists as Horowitz and Gould in the same article. Usually not paired, they’re my two favorite pianists in the world.