Jonathan,
So you did [mention Michael Nyman]. Apologies - especially as I actually read your post with particular interest and agreed with the comment about Gladiator. My short term memory is shot to buggery these days, and I expect I'll soon be in a Home.
As well as Holst, Gladiator reminds me a lot of Conan the Barbarian, which is a fave. Have you heard Conan the Destroyer? Quite similar to Conan the Barbarian, as you'd expect, and almost [but not quite] as good. Basil Poledouris did Robocop as well, which when I first saw it seemed to have an amazing similarity to C the B, especially the main theme - just a couple of notes switched.
What you say about Michael Nyman composing before the movie makes sense - it probably explains the differences between the classic[al] older stuff and more recent things like Gattaca, which have a much more traditional 'soundtrack' feel and if you didn't know it, would not realise was Nyman at all.
Doubtless you know the lovely 1492 by Vangelis, but what are his other soundtracks like? I see from Amazon that he's done quite a lot, and apart from Chariots of Fire [overkilled for me, & could never personally face it again, effective though it is] Any recommendations?
I know that at the time Vangelis blocked the release of the proper Blade Runner soundtrack, thinking for some odd reason that it wasn't worthy of release [first widespread use of sampling technology incidentally .... can't think of the gadget - Fairlight, maybe?] and so Warners, justifiably peeved, rustled up an orchestral, and rather manky version. A vaguely similar sort of thing happened with 2001, when CBS, to cash in on the prevailing mania popped out a version of the 'soundtrack' culled from their classical catalogue, in the hope of fleecing a few punters who hadn't noticed the official MGM version. The 2001 selections took up the first side of the disc, but then on the second side, some genius in A&R put an astonishing thing called A******* - A Space Opera. Blew the '2001 soundtrack' away - a mixture of electronica, choirs & orchestra. But what was it called? And by some miracle, is it available in any form? Me and my pals spent many an evening in darkened bedrooms lit only by red bulbs being astounded by this [it was 1968, remember] I suppose it must have been a pioneering example of 60's musique concrete, but I would dearly love to hear it again......