Firefox is the default browser in recent versions of Ubuntu. It provides a safe, customizable, convenient browsing experience. I prefer Firefox to other browsers for the greater customization options, including a vast array of useful add-ons.

Evotlution is the default email client in recent versions of Ubuntu. It's a pretty simple, yet powerful client, with support for features like an address book, spam filtering, and all the basic features any email client should have. I actually prefer it to Thunderbird.

gedit is the default text editor included with Ubuntu. It's far more powerful than the standard Windows Notepad, with support for syntax highlighting in various languages. It provides a tabbed interface, much like modern web browsers. Spell check, printing, and multiple language support are all included features. gedit is very easy for basic use, and has plenty of features for advanced users.

Empathy is a multi-network chat program. You can use it to connect to your Yahoo, MSN, AIM, ICQ, and other chat network accounts. All the basic features should be supported for the major networks, but things like webcam chat may not be supported.

Brasero provides a solid method for burning audio, data, or video CDs and DVDs. It also has support for burning .iso disc images, and disc copying.

In recent versions of Ubuntu prior to 11.04, OpenOffice is the default office suit. LibreOffice should be available, should you choose to switch. But they're basically the same, for now. OpenOffice provides nearly all the functionality of the Microsoft Office Suite, completely free. Microsoft Office file types are supported, as are other default open-standard formats.

Rhythmbox provides the common functionality of various modern music players, such as multiple audio formats, playlists, equalizer, streaming, and visualization.

VLC isn't installed by default in Ubuntu 10.10 or 10.04, but it should be. Totem movie player is the default video player, but VLC is better. I recommend installing VLC from the software center.