You get what you pay for with Soft synths.

I'll try to rank the ones I have, and only include Gm synths to narrow it down.

I) Colossus (Kontakt) cost: $$$$ forget it. But it's extremely good even for serious media scoring.It has GM, not that that makes any difference at this level.

2) Hypersonic. Cost: around $200 street, but you might get it cheaper if you dig around.
Excellent library for the price and very resource friendly (can run well on almost anything). Requires dongle.

3) Garritan Jazz. Cost: about the same or cheaper than Hypersonic. It is very good and would be my second choice after hypersonic.

Then there's 'Bandstand'. Cost: (about the same as Garritan) . Not bad if you don't mind dealing with Native Instr's total lack of support.

The remaining (the affordable ones ( ) You probably have tried yourselves so I won't bother.