I have been interested in VSTs and other synthesized sound tools since I started using Ableton Live about 6 years ago. They have helped bring a richness to my songs. The very best VSTs use processes like “acoustic modelling,” and  are expressive and complex, mimicking Rhodes electric pianos, Hammond Organs, string sections, guitars, brass, woodwinds, and in the case of Applied Acoustic Systems from Montreal, a wide variety of highly unusual and exotic sounds. I am a huge fan of a few of their tools. When I bought a Korg Micro-kontrol I got two lite versions of their software: Lounge Lizard and Ultra Analog. These two sound banks really helped me get some thick and authentic musical tones into my music. Recently AAS released some great new sound banks, and even a freebie sampler so you can try out a bunch of sounds for free! All you have to do is download Swatches and run it as a VST inside your software. There are 48 sounds to try and I guarantee they will blow your mind.

http://www.applied-acoustics.com/swatches/overview/