QUOTE(Nihon89 @ Aug 8 2008, 04:46 PM)

I hear alot about "vanilla" when I'm looking at mod descriptions, but I never have found anything that actually tells me what it is exactly.

Vanilla is often used to describe something as being without modification or altered or "the norm".
So vanilla Oblivion is the out of the box game with no mods / additions / tweaks.
It is even used to describe a form of sex but that's another story.
Cheers.