I have used Scrivener since its original beta for all my writing, because it is not a word processor, but a complete writing environment. All the tools I need are at my fingertips. All research, notes, outlines, sketches, drafts, ideas, photos, and writing tools like dictionary and thesaurus are now open on my desktop.
I have tried every writing program available and none compares to the simplicity and power of Scrivener. Keith Latte, the developer has created a uniquely user definable workspace that each writer can define to meet your own needs. Whether you write intuitively, visually, outline, or need extensive research, all are accommodated in Scrivener.
A Windows version is currently in beta testing. If you are a Mac user I know no better way to organize and fulfill all your writing needs.