First of all my favorite vst is IK Multimedia Philharmonic. The best quality Ochestral sound collections. I use this in all my stuffs.
My second vst is NEXUS. Its has over 10 GB of Sound Expansion packs but not comes with nexus. you have to purchase it.
My third vst is Spectrasonic Atmosphere. It has a massive 3.7 gigabyte core library with a powerful sound, nice interface and synth engine for designing the sounds, and creating your own sounds.
My fourth vst is ACE from u-he. Its my favorite synthesizer for mashup synth. It has nice interface and powerful sound editor. Its also features midi learn option for assigning it to the midi analog hardware.
And my fifth vst is Absynth 5 which is a synthesizer with 1,800 preset sounds. It has a categorized sounds like trance acoustic and much more. We can easily find our desired sound from this feature. Also it include an awesome sound editing feature to tweak sounds.
Also the most important feature these plugins are that they come in 64 bit also. All are compatible with Windows 7 Ultimate 64 bit. I have tested them
All are tested with FL Studio, Ableton, Cubase.
I'll give you more later. Add me on facebook and Twitter for updates and more