These sound libraries are E-MU's originals, taken from their hardware units and ported over to the software realm. They sound great.
I'm looking to purchase the hardware versions of these libraries to use without a computer, so I won't be needing these software versions anymore.
I'm asking for 1/2 of street price, which means I'm selling the entire bundle for $75.
Quick note: I believe the ROMpler that plays these libraries is Windows-only, so if you're using a Mac, you will need a Mac-based sampler capable of playing back E-MU's format, and I don't know whether such a thing exists.
Mo Phatt X - Definitely a gem. One of the few professionally-produced sound libraries intended for hip-hop/dance specifically. This is one of my personal favorites.
Protean Drums X - A great source of all kinds of sounds of drums -- acoustic, techno, hip-hop, rock, pop, etc. The library actually comes with 513 professionally-produced kits, so you can find whatever flavor fits you and your song.
Planet Earth X - Large collection of "ethnic" instruments and percussion -- oriental, middle-eastern, indian, etc. Definitely imparts a specific, unique flavor to your tracks, and is a lot of fun to play with.
Proteus VX - E-MU's freeware ROMpler. Comes with its own high-quality soundset (especially for freeware!). You can go to E-MU's website and download this for free, but I'll send my backup disc to you, so you'll have a hard copy and won't have to hunt down the download link on their site.