I came across this website that lets you try sample libraries out for free by transferring MIDI and the resulting audio output to you through the internet. All you need is a PC or Intel Mac (Running Windows) and a MIDI keyboard. You can sign up for 30 min "sessions" where you get to try out your specified sample library.
So far, the libraries you can check out are:
Artist Complete
Complete Classical Collection 2nd Edition
Chris Hein Horns V1
Chris Hein Guitar
Chris Hein Bass
Drums Overkill
Ethno World 4 Professional
Galaxy II Pianos
Latin World
Orient World
String Essentials 2nd Edition
RealGuitar 2L
RealStrat
Cult Sampler
Independence Free
Convolution Space
Project Sam Symphobia
Ivory Grand Pianos,
Ivory Italian Grand
I'll be checking out Project Sam Symphobia for my test run.
Link to the website:
Try-Sound