There is the Strong controversy going on between the Unity and Gnome 3. The controversy started when Unity has been choosen in Ubuntu 11.o4 Natty Narwhal. On the Other hand Gnome how condemn themselve being the father of Linux distribution has also been surrounded by conterversery. Gnome 3 has wide variety of changes since Gnome 2. Most of the popular Linux distribution like Ubuntu, Fedora comes under Unity and Gnome3. But the beauty of open source makes user can do whatever they want with their Linux distribution. They can change it according to their wants. Here are some of the alternative for the people who want to try other different Linux desktop enivornment.
If you are using Kubunu,OpenSUSE, Mandriva and PCLinuxOS Then KDE might be the familiar to you. KDE looks somewhat similiar to microsoft windows. Therefore there will not be problem with the user regarding interface who want to switch from windows to Linux distribution. Major advantage of KDE are huge amount of application available on all platform supported by KDE development. huge community support, provides other more options.
LXDE known by lightweight X11 Desktop Enivornment was started in 2006 and has been able to establish them as fast performing and energy saving desktop solution. If you have old computer with lower resouces then you can simply choose LXDE. LXde can be run on various popular Linux distribution such as Ubuntu, Debian, fedora, Ubuntu already has standard for LXDE called lubuntu. Therefore ubuntu user simply can choose lubuntu while installing it. LXDE has simpliar application panel like Ms windows. Therefore user migrating from windows to Linxux operating system find it similar.
Enligtenment is lean, fast, modular and every extensible window manager for Linux. Enligtenment libraries has power million of system from mobile phone, desktop, laptop, game system and more. It is build on the top of building blocks known as EFL(Enlightenment foundation libraries).
XFce is another desktop enivornment or windows manager for Linux and UNIX like operating system. XFCE is fast an designed to run on low system resources. The panel has different features like switch between opened windows. lanuch application, switch workspaces and menu plugin to browser application or directories.
Fluxbox is another window manager for Linux user. Its build on C++ based on blackbox 0.61.1 code. The various different features on Fluxbox are tabbing, grouping, a long list of keycommands, chainable, keygrabber, fully editable menu and so on. Fluxbox uses its own graphics class to render its images on the fly. By using style files, you can determine in great detail how your desktop looks. Fluxbox styles are compatible with those of Blackbox 0.65 or earlier versions, so users migrating can still use their favourite themes.