Gator, you might want to take a look at my site about "Waterworld (rejected)":
http://www.rejectedfilmscores.150m.com
"Great" is a subjective view. Here are some movies scores which need a release:
Duel -- Billy Goldenberg
Back to the Future -- Alan Silvestri (complete and remastered)
Spartacus -- Alex North (complete and remastered)
Gladiator (rejected) -- Goldsmith
Eaters of the Dead (rejected) -- Graeme Revell
Troy (rejected) -- Yared
The Big Blue -- Bill Conti
Dr. Detroit -- Lalo Schifrin (I liked it, sue me)
Joe Kidd -- Lalo Schifrin
The Satan Bug -- Goldsmith (If they can ever find masters)
Conan -- Basil Poledouris (complete and remastered)
Star Trek 2, 3, 5 and 8 -- Horner, Goldsmith (complete and remastered)
Something Wicked This Way Comes -- Horner
Something Wicked This Way Comes (rejected) -- Georges Delerue
The Journey of Natty Gann -- Horner
Jake Speed -- Mark Snow (complete and remastered)
Coming To America - Nile Rodgers (complete)
Staying Afloat - Dennis McCarthy (.com)
A Christmas Story -- Carl Zittrer & Paul Zaza
Emporer of the North -- Frank DeVol
Suicide Kings -- Graeme Revell
Stalag 17 -- Waxman?
Joe somebody - George S. Clinton
Lots of rejected scores
And more. And this didn't even include TV shows.