I've worked almost exclusive within a Linux environment for nearly 3 years now, and currently using Ubuntu as my main desktop OS...
http://www.ubuntu.com/
For browsing, Firefox is all you need.
For development - I use "KDevelop", which although is officially a KDE app it runs fine under Gnome which is the default desktop environment installed by Ubuntu . You can install it, and just about any other Linux app online simply by clicking System > Administration > Package Manager.
For FTP / SFTP, "gFTP" does everything you could want - and has a superb bookmarking system that is far easier to use than most other FTP client's favourites system.
Graphics of course there is The Gimp (installed by default); and a great SVG (scalable vector graphics) editor called
SodiPodi (can be installed directly - see above) - ideal for designing logos etc. that need to scale well.
For multimedia - simply go to Package Manager and get
Video LAN installed - there's nothing it can't play. For MP3's I use xmms which is a Winamp clone.
OpenOffice.org (installed by default) has come on along way and is perfectly usable for just about any word processing / spreadsheet task you can imagine, and will open and save MS Office documents as well.
Gaim (GNU Instant Messenger) - again installed by default - supports virtually all IM networks, and works fine if you don't want any bells and whistles like video conferencing and stuff like that.
But the best thing of all, is Linux just keeps on working. When you install things, you just get the app installed; you don't get stuff added to your startup group, new system tray applications taking up resources - none of that nonsense. In 2 years time your system will boot up just as fast as it did when you first installed it.
Highly recommend - you won't look back
