Those days (1x versions) Gnome used to give users a lot of features and options to customized the desktop (even better than KDE in features) but with the introduction of the 2x "jump" a huge list of those GUI configuration options were removed. So in a way, the Gnome 2x desktop was totally different one to its predecessor.
Just like that the recently introduced Gnome 3 also brought a total re-design of the desktop GUI and computing in general thus just like with the 1->2 migration, it received a lot of criticism (both negative and positive ones, yikes!).
Anyhow, sorry about the "short rambling, introduction", if you're one of the fans of the new Gnome 3 apart from all those issues, and I gotta admit Gnome developers always had an excellent (highly relative) ability to provide good looking themes (although very little customization available) but after using it for months, if you're already bored with the themes that comes with it and looking for something that looks beautiful, then perhaps the Elementary Luna theme for the Gnome Shell might get you interested :).
*. This is a complete theme suit but you'll have to get an icon pack a wallpaper separately to the original shell theme (links below). But of course you can skip the icons and the wallpaper if you like as well.
*. Comes with a bit darker colors and my personal favorite, the awesome Blue color! :D.
*. There's a separate lighter version of the theme is also available if you don't like the darker color choices which resembles a lot of Mac OSX.
*. This is only compatible with the Gnome Shell 3.0. So if you're using the 11.10 Oneiric Alpha 3 and the Gnome 3.1.4 latest builds then this may not work.
How to install it?
1. The installation is quite simple actually. Just download the shell theme from here first.
I'm gonna quote the author Danrabbit here...
Backup your theme directory first. Extract the zip file and rename "gnome-shell" directory to "theme" and copy to /usr/share/gnome-shell/. This path is usually where GNOME Shell is installed.2. If you want the icons, then get them from here.
Restart GNOME Shell by Alt, F2, then type r and press enter.
3. Get the beautiful Elementary Luna wallpaper from here.
Yep, that should do it!. Enjoy.