Best Classical to "broaden" listening arena?

I have come to "love" Yanni, Norah Jones, Sade, Sarah Brightman, etc.

Since I really appreciate individual instruments & have a fairly high end system with separation as a strong point--I am interested in which composer / group I should start my "classical" specific collection with?

On Audiogon, Classical seems to be the highest sold category thereby indicating high collectibility & listening by educated music lovers.

Thx in advance for your opinions,

Dr David Joned
I assume you are looking for more specific recommendations, and especially some that are well recorded, spacious, and engaging. For violin, try some of Hillary Hahn's Sony recordings, such as Mozart, Barber & Meyer, Brahms & Stravinsky, Mendelsohn, and Elgar. For cello and piano, try Zuill Bailey's Telarc recording of Brahms works for cello and piano. All are quite accessible.
If you have streaming capability check out WFMT Chicago. Best classical station in the US. Special shows St. Paul Sunday and Exploring Music will raise your knowledge and focus your interest. Other great show besides daily programming
Check out:
I believe St. Cecilia was the patron saint of music. This is a site dedicated to classical music. Not religious in any way, I think the title is from "Hail Bright Cecilia" by Handel or Purcell or some such.
Well, as usual, you have Exceeded my expectations!!

Thank you very much as I have enough great input to put together a plan and begin my "classical" journey.