I love to make my Gnome DE as functional as possible rather than making it decorative. I detest the idea of putting those compiz, beryl, emerald or whatsoever they are called. The default metacity is good for me, except for its minimize/maximize effect - which is a real joke. Minimizing windows in Gnome (without compiz fusion) displays a kiddish (often annoying) style of showing a black border closing down into the windows list panel. And there has been no easy fix to avoid it. You can turn this minimization effect off by enabling reduced_resources option through gconftool-2 or gconf-editor, but there you will see a wireframe while dragging an application window, and sometimes you'll see really troubled look in restoring/maximizing a windows.
The real fix to avoid the silly gnome metacity minimize effect is a 2-step process:
Press ALT+F2 and type "gconf-editor" without quotes.
Search for a value "Reduced Resources" (you'll find it at /apps/metacity/general/reduced_resources )without quotes, and check-select it as shown in the pic below.
While you are still in gconf-editor, search for a value "accessibility". It will result in couple of results, check-select the one at /desktop/gnome/interface/accessibility as shown in the pic below.
That's it! Now your gnome desktop will act quite responsive without those ugly minimize effects.