1) Ubuntu Tweak
Ubuntu Tweak allows changing all the itsy-bitsy pieces of Ubuntu desktop OS. It is the equivalent of TweakUI for Windows. You can achieve the same results by using the gconf-editor tool in Ubuntu. Ubuntu Tweak also helps install third-party upgrades in a simpler fashion so it definitely gives a new boost to your clumsy Ubuntu desktop and increases UserExperience.
The Screenlets application provides access to hundreds of Google Gadgets and other open source widgets, like Remember the Milk or Google Calendar. Ubuntu can also hide the Screenlets until a key is pressed – to get it done you will also need to install the compizconfig-settings-manager package.
This is what they say:
Screenlets are small owner-drawn applications (written in Python) that can be described as “the virtual representation of things lying/standing around on your desk”. Sticknotes, clocks, rulers, … the possibilities are endless.
Handbrake works with the VLC media player to rip a DVD into a video format file.
This is what they say:
HandBrake is an open-source, GPL-licensed, multiplatform, multithreaded video transcoder
Yakuake is a terminal application with tabbing features that is fast with custom coloring and shading and offers an integrated experience. It has been coded for KDE-based systems but it will run on Ubuntu. You may want to make this program start up with system startup.
UPDATE: They are updating their website which currently says:
The website is under heavy construction. Please be patient! The version 3.0 of YaKuake is on its way with great new features.
UNetbootin turns any Linux operating system distribution into something that boots from a USB stick. You can custom-make your own operating system with a chosen kernel and UNetbootin makes the process very easy.
Songbird is an attractive and adaptable music app for Ubuntu. It can manage your iPod, grab album art, play streaming web tracks and has a host of add-ons that are able to mash up web data and you may also customize how this app looks and feels.
This application is controlled by text files and you can mix and match the features and data you want displayed. Conky can make available any data you want on the desktop and can keep it updated.
8 ) VirtualBox
VirtualBox provides a trimmed-down version of XP that is easy for a newbie yet very customizable as a taskbar in your Ubuntu desktop is much like VMWare but the only difference is that it’s OpenSource. Its primarily for the enterprise users but could be used on any machine for virtualizing. So if you are not yet ready for migration to Ubuntu then you can get a taste of it by installing it on top on VirtualBox i.e. your virtualized Ubuntu experience.
DropBox integrates as a folder in your home directory and synchronizes the files with a 2 GB free account and offers access and notifications from system tray.
10) GNOME Do
GNOME Do is a productivity tool and application launcher for Ubuntu. You can assign keyboard shortcuts to open applications, use terminal commands, update Twitter, etc. GNOME Do also includes a desktop clock.
Top 10 Apps that Boosts Ubuntu’s User Experience | ProgrammerFish - Everything that's programmed!