TAXI.com

I made the mistake of googling this earlier...there are A LOT!

What are people's favourites here?

I'm looking to write pieces suitable for film & tv (spanning as many genres as I can) so any recommendations on atmospheric style libraries, great sounding orchestral stuff, unqiue synth sounding, even the weird and wonderful would be appreciated...

So far I can't get enough of anything Spitfire Audio has their name against (about to invest in the new Stratus beast that looks insane judging by the youtube videos), a few piano one's I've invested in too like Felt Piano, Vocalise is also a favourite of mine

We could go on forever, here...

I was going to say Spitfire, many complain it does not get stupid loud (and I am all right with that, one can always layer, no? ), Cinesamples is a good contender.
I like SampleHero stuff quite a lot, Orange Tree for guitars, Sonokinetic, and a couple more I do not remember off the top of my head because I have too many

Hi - there are so, so, so many amospheric instruments to download, learn, tinker and use (and then forget that you've already installed them) which you can further delay, shape, and distort in to so many new sounds that just about any library will do.
I suggest you check out the post by mbantle in 'recommended gear' about free stuff because, well, free.
best-free-stuff-2020-t144473.html

I would get every one of Spectrasonics’ VI’s before anything Native Instruments. I use Omnisphere and Keyscape on every track. I use NI Komplete Ultimate 12 too, but you need Komplete Ultimate to get their good film libraries (wait for summer sales which is 50% off).