Currently:
Best value are the Exponential Audio reverbs for $10-$30 each (R4, R2, Nimbus, Phoenix). Damage 2 for $199 exceeded my expectations. The Spitfire Audio Everything Collection is a phenomenal grand set of libraries, though not inexpensive. VSL Synchron and BBO series are terrific. All 4 Orchestral Tools Metropolis Arks for $1,000 was a great deal.
Back in the '90s:
The Tascam DA-88s and then Pro Tools, Genelec speakers, MOTU's Mosaic, MTPs, VTP and Digital Performer, and the Mackie 8-bus & Expander consoles all let composers do their thing!