Music help needed

Anyone know a good classical music compilation or series of compilations?  Not  the most well known pieces, something with Mozart's B-sides (like Turkish March),  Vivaldi's other stuff, and lesser known composers like Saint-Saëns (Carnival of the  Animals)?  Something with the "one hit wonders" on, slightly obscure but still good stuff.

I used to have a great classical series on cassette and by the third set of tapes you were well off the beaten path, which is exactly what I want, not a "Most relaxing classical music" kind of thing.  There's a lot to wade through in the classical section of Borders, so any help would be appreciated.