An often-overlooked one is LaTeX Editor, which is available for both Unix and Windows. You do have to muck about a little bit with plumbing between MikTeX and GhostScript on Windows to make it work, but once you get it kicking it's got a nice set of features, and gives you side-by-side code-and-DVI preview with reverse-linking (click on the DVI and it takes you to the relevant code fragment in the LaTeX file). It handles large projects extremely well; a lot of people in my department use it for their dissertation.