Desktop environments or shells for Ubuntu

GNOME Shell is the “official” shell developed for GNOME 3 by GNOME
sudo apt-get install gnome-shell

Unity (Installed by default)
Founded in 2010, the Unity project started by Mark Shuttleworth and Canonical has gone on to deliver a consistent user experience for desktop and netbook users alike. Putting great design at the heart of the project, Unity and its technologies such as Application indicators, System indicators, and Notify OSD, have strived to solve common problems in the Free Software desktop while optimizing the experience for touch, consistency and collaboration.
Unity is the default shell for GNOME 3 used by Ubuntu
sudo apt-get install ubuntu-desktop

Xfce is a lightweight desktop environment for UNIX-like operating systems. It aims to be fast and low on system resources, while still being visually appealing and user friendly. It comes with various additional apps and panel plug-ins which greatly enhance the functionality of the DE.
Ubuntu has an XFCE spin called Xubuntu it is recommended to install it from the official image (.iso) that can be downloaded
sudo apt-get install xubuntu-desktop

LXDE (Lightweight X11 Desktop Environment)
LXDE is an extremely light desktop environment that focuses on high performance and low resource usage. It is currently the default desktop environment used by Lubuntu
Ubuntu has an LXDE spin called Lubuntu it is recommended to install it from the official image (.iso) that can be downloaded
sudo apt-get install lubuntu-desktop

KDE is probably the second most well-known DE available after GNOME
It is recommended to install it from the official image (.iso) that can be downloaded
sudo apt-get install kubuntu-desktop

Cinnamon is a Gnome-Shell desktop fork. It is not strictly a Gnome-2 interface, although the developers aims are laudable – to produce a simpler more traditional desktop interface.
The desktop shares many traits of its closely related cousin – and can be extended through specific Cinnamon extensions.
Requirements are the same as Unity 3D & Gnome-Shell, in that it requires a 3D Graphics accelerated graphics card.
This is subject to change – Gnome-shell Mutter has been forked as well – called Muffin. It will be interesting to see what future requirements this will bring

Gnome Panel (Ubuntu Classic/Gnome Fallback) (Discontinued as of Gnome-Shell 3.6)
This is the basic or classic GNOME desktop, ported to use the new GTK3 and other modern technologies. It is the same program that was used in earlier versions of Ubuntu. But like everything else, there’s been improvements in the new version.
It still has the classic menu, but the System menu is gone since we now use the System Settings panel.
It can be customized the same way that Gnome Panel 2 was customized, except that you need to press and hold Alt while doing so.
It has all the same features that we previously had, but with fixes to make it more stable and useful: applets are grouped to the left, center or right, so applets never get shuffled, like in Gnome Panel 2. And the switch to GTK3 means much better support for vertical panels.
The classic appearance looks different by default in 11.10 (fixed in 12.04), but that’s easily changed;

Pantheon (In Development)
Pantheon is the desktop shell made for use in elementary OS Luna and later. It can also be set up for use in Ubuntu, however

Awesome is a desktop environment which masquerades as a window manager. By default, it comes with a basic top panel with a systray that can hold your favorite applets from Gnome, Xfce, etc. There are several well-known “widget” libraries which extend Awesome’s basic functionality

Enlightenment (E)
Enlightenment sets itself apart for being very focused on eye-candy while still being extremely lightweight.

MATE is a fork of GNOME 2 created when GNOME 3 was announced and some users wanted to keep the traditional GNOME 2 interface going. It aims to be as close to traditional GNOME 2 interface as possible. The project is now primarily supported by the official Ubuntu MATE spin since 14.04.

Mythbuntu uses XFCE, but also comes with some extra customizations. It is primarily intended for media PCs for use with MythTV.

QTile is a window manager written entirely in Python. It’s highly configurable using the Python language, and you can script it to do mostly whatever you feel like. As the name implies, it’s a tiling window manager, which means you get a highly organized desktop

Chrome OS Desktop Environment
This is the operating environment of Google’s Chrome OS, and as far as I know, it works only on 64 bit machines.

i3wm (improved tiling wm), is a dynamic, and tiling window manager. It is one of the simplest and cleanest tiling window manager, which keeps emphasis on simplicity, both of the code and configuration.

This is a very lightweight desktop environment, available for Ubuntu.
Steps to install:
sudo add-apt-repository ppa:razor-qt
sudo apt-get update
sudo apt-get install razorqt

Deepin DE
I am impressed a lot by the Deepin DE, If you too want to install it then open your terminal and type as
sudo gedit /etc/apt/sources.list
Then add these source line at the end of the opened file( Dont do anything else)
deb raring main non-free universe
deb-src raring main non-free universe
Now save & close that file and back to terminal.
paste these lines one by one
gpg –import deepin-keyring.gpg
sudo gpg –export –armor 209088E7 | sudo apt-key add –
Then we are almost done. in the terminal paste these lines one by one
sudo apt-get update
sudo apt-get install dde-meta-core
Thats it, That will install deepin DE in your computer and from login screen you can choose the DE

Trinity desktop environment is another option available on Ubuntu.

Read the details from source: