I think it depends on the platform you're using as well as what editor you prefer. Any more details?
In the interim, you might look at this:
http://gummi.midnightcoding.org/?page_id=2
I've not used it, but it looks promising.
This one is nice: http://gummi.midnightcoding.org/ has live preview and is very simple.
And if you are in a hurry (or on the go) (or want cloud solution) Latex Lab http://docs.latexlab.org/ is implemented on top of google docs.
These might do what you want. LyX has many templates that can save you a lot of formatting.
Package: gummi
Description-en: GTK+ based LaTeX editor with live preview.
Gummi is a LaTeX editor based on GTK+.
The basic features are:
Package: lyx
LyX is an almost WYSIWYG-frontend for LaTeX. It makes the power and typesetting quality of LaTeX available for people who are used to word processors. Since LyX supports LaTeX's concept of general mark-ups, it is even easier and faster to create professional quality documents with it than with usual word processors. It is also possible to use LaTeX commands within LyX, so nothing of LaTeX's power is lost.
You can extend the functionality of LyX by installing these packages:
Homepage: http://www.lyx.org/
I did this for a while. I ended up settling on gummi as my LaTeX editor, and defined a snippet to type \left ( and \right ) for me in a way that interrupts the writing of the content less than \paren{}.
Like pretty much everyone else in this thread, I'm going to recommend LaTeX. I highly recommend you use an editor that supports code snippets like gummi, or learn vim and get the SnippetsEmu plugin. Both of these support snippet chaining, which allows you to start using a snippet while inside another snippet. This greatly reduces the amount of typing you need to do and makes it so that you rarely have a mismatched set of brackets.
>I use WhizzeyTeX so I'm writing my boring paper in emacs AND a wysiwyg editor. Beat that.
Gummi does that. It doesn't have all of the neat editing tricks you get in emacs, but it's at least all in one interface.