The two libraries I use most often these days are Hollywood Brass Gold and CineBrass Pro, and for me, my first choice is Hollywood Brass. I feel their samples are more realistic, especially the horns. Having said that, the mics in HWB Gold are quite distant, so they can sound quite far away. CineBrass Pro has a wider variety of mic placements so you can get a wider variety of distances in your placement in the mix. However, it only includes some passable solo Brass, some muted trumpets/trombones, a large (12) horn ensemble, some low brass and some ensemble chords and FX. HWB Gold has a wider variety of ensembles (e.g. solo horn, 2 horns, 3 horns, 6 horns), plus a bunch of FX (which compliment the Brass FX in EWQLSO). Plus, CineBrass has an extraordinary (I would say amateurish) amount of hiss and noise in some of their samples. Hollywood Brass doesn’t have that, but I think they have processed that out, which loses some of the characteristic brass quality.
Pricewise, EastWest generally have amazing deals at summer and x-mas time (I think you just missed a BOGOF for Black Friday), so it is possible to pick up the already reasonably priced HW Brass Gold for 50% off or less if you time it right. Cinesamples have 40% right now, so if you’re quick you could get a bargain.
Wishlist wise, in theory I’d love samplemodelling’s Brass as they are versatile (suited for cinematic/pop/classical, etc.) and can sound indistinguishable from the real thing (keep in mind, I’m a brass player, so I know what they’re supposed to sound like). In practise, I’m concerned about how much time and effort would be required to create as realistic a sound as I would like. I’d also love Hollywood Brass Diamond and CineBrass Core (what I wish I’d bought instead of Pro).
I have no experience with Spitfire’s Brass, though the horns sound pretty amazing. Orchestral Tools are also hard at work on Berlin Brass which, if their woodwind library is anything to go by, should be pretty amazing. I’ve also heard good things about Project Sam’s Orchestral Brass Classic, but again have no experience in dealing with it (and frankly am not a fan of Project Sam’s general sound quality). I used to love VSL’s Brass and some of them are still awesome (Epic Horns), but some of them now sound like toys to my ears.
I guess it depends on what kind of music you’re looking to make. I’d probably recommend CineBrass Core, as I can see you write some epic dramatic music, and its ensembles are perfectly suited to that. Hollywood Brass Gold is in the same ballpark price-wise, has more variety of ensembles, I’d argue a more realistic sound, but has only one, reasonably distant, mic position. But neither would be good for more pop/commerical stuff.