Gerhard 4 and Rubbra 5 safely bagged, along with Pickard's
The Flight of Icarus.
I got to know both Tippett 2 and 3 (and 1) through the Hickox recordings, which were the most easily available at that time (mid-1990s; in fact I may have been picking them up as they were released, come to think of it). They somehow didn't interfere with my taking a great interest in this music, although the 2nd's never really sunk in very deep. The 3rd is my favourite by some distance of the symphonies. Of course the Davis recordings are all boxed up and repackaged at such a cheap price on Decca now that there's really no reason not to get those.
I don't really know why I haven't got to know the Tippett symphonies; I really like
The Rose Lake, the Corelli, the Concerto for Double String Orchestra,
The Midsummer Marriage and
The Knot Garden; a rental DVD of
King Priam arrived today, but I've been occupied with the Proms this evening.
With the two R's on the Dutilleux suggestion. Especially the two symphonies and the violin concerto. And Mystère de l'instant, wonderful piece: I don't think my recording of that piece is on Chandos but I'm pretty sure Yan-Pascal Tortelier did the complete orchestral music so it must be in there somewhere. Sur le meme accord won't be, as it's much more recent, but I wouldn't worry about that if I were you: watered down late Dutilleux, if there's anything to be got I haven't got it yet, and I suspect there isn't.
I shall definitely choose some of these.
I know the Ondine catalogue quite well from my harmonia mundi distribution days and will try to think what else there you might like, besides the Roussel which as Richard says is very good indeed. Timpani is an excellent, excellent label (and I've never even worked for or with them!): pity that's not there.
Sadly, the Eschenbach Roussel isn't there. I have quite a few of their Rautavaara and Vasks discs, and might try out there latest Panufnik one, and some Saariaho. Those Helsinki PO/Segerstam Sibelius symphonies could well get the credit card itchy in time...