Who was your first

Does "Chicago" count?

How about "Blood Sweat and Tears"?.

Didn't a lot of folks get first exposure to some finer and more accessible elements of Jazz through these guys?

Mapman
Your examples are not Jazz in its strict sense and what are "fine and more accessible elements" of Jazz? To me, Jazz is essentially "black music" and for sociological reasons alone, think of Mingus, Parker, Miles, it is not necessarily intended to sound "fine" but rather "dirty" and is essentially, when it comes down to the nitty-gritty, a musical answer to the social ostracism suffered by the Afro-American community in the heyday of Jazz. Black musicians will tell you, that later this music was "stolen" from them by and became mainstream. Just to add to what Cwlondon said above.

Ella Fitzgerald - specifically the Rome 40th birthday concert.

The jazz domain by black americans is well documented, but we would be in error not to acknowlege the gifts of white musicians of the same period such as Gerry Mulligan, Chet Baker, Dave Brubeck, Bill Evans,Red Rodney, Ira Sullivan,Shelly Manne, Buddy Rich, Art Pepper, Pepper Adams and the list can go on and on. To me jazz is so much more than a black/white idiom. It is the music itself and the artist that put it forth. During the heyday of the bop and later bebop revolution in jazz all the greats both black and white pushed this music to very lofty heights indeed. And they all worked together in sessions and live concerts to give us this gift.

Ferrari's post beat me to to it.Jazz is not Black or White.It is America's Music and appreciated all over the world