Best full orchestra recordings?

In my travels to hi-fi shops I've listened to some recordings of full orchestra works, but my music collection suffers from a conspicuous absence of such recordings. I have what looks like a "greatest hits" kind of collection in this area (Copeland, Stravinsky. etc.). Since putting together a high-end system I am much more appreciative of these types of recordings. I know there's a wealth of information out there: any recommendations of orchestral works, new or old, that should be in one's collection?