Rightzoom for OS X lets you maximize your windows – Windows style!
A friend of mine who recently switched from Windows to Mac was very annoyed: clicking on that green button in a window in OS X didn’t maximize the window. It just resized. Very annoying, he thought, and started googling. And he found something good: Rightzoom.
With Rightzoom enabled, whenever you click the green button on your windows, they maximize. Very nice indeed. Best of all is the option to only enable the maximize function if you hold down the option key while you click. This is the way I prefer.
For me, this is definitely a keeper.
More info and download: http://osx.iusethis.com/app/rightzoom