On Mac OS X it is just a breeze to install GNU Emacs, either the stable or the development version.
I am assuming you have the wonderful HomeBrew installed. First, as always when installing anything, make sure you are up to date:
The formula has a bunch of options that you can use to tweak your version. Most of the time you will not want to change these.
I, however, want to enable the Emacs.app (highly recommended!) you need to add the cocoa build. While we are at it, we will also enable gnutls and imagemagick for a better experience.
On my machine it too 2 minutes 42 seconds to do the full installation. Brew will take care of all the dependencies and the compiling.
Finally you will want to make the Emacs.app available in the Applications folder. Brew also facilitates this by providing the linkapps functionality.
If you want to install into your ~/Applications folder instead, then you need to create your own symbolic link.
That is it. It is very easy and allows you to stay up-to-date using Brew.
Alternatively you can download a prebuild package from EmacsForMacOSX. This package also contains a lot of sane defaults.
A bonus for this method is the availability of pretest and nightly builds (same as devel with Brew).