One of the many useful additions to the internet's body of knowledge in the collaborative arts has been the large number of repertoire lists that can now be found on Wikipedia. Here are links to some of the more comprehensive ones I have found:
List of compositions for piano and orchestra
There are several other rep lists for wind instruments and art song traditions that have not been included here as they are not yet complete enough. And to think that a scant 15 years ago these lists of works were painstakingly compiled and circulated via photocopies as a select body of knowledge circulated within accompanying studios. I still have copies of Gwendolyn Koldofsky's repertoire lists that have been handed down from studio to studio over the years...