Here is a list of the programs which I prefer using to get my jobs done. I would rather not pirate programs or pay stupidly large amounts for them, so I go with the third way:
<table border="1"><thead>
 | Task |  Windows (Vista) |  Linux (Ubuntu) |  
</thead> <tbody>
 | Media |  
 | Music player |  foobar2000 |  Rhythmbox |  
 | Editing sound files |  Audacity |  
 | Video player |  VLC |  
 | Subtitle editor |  Subtitle Workshop |  ? |  
 | Video transcoder |  MeGUI, Avisynth, K-Lite |  mencoder |  
 | 3D animation |  Blender |  
 | DVD authoring |  DVD Author GUI |  ? |  
 | Image editing |  GIMP |  
 | Web |  
 | Browser |  Firefox |  
 | Editor |  KompoZer |  Quanta Plus |  
 | Blog website |  Wordpress |  
 | Publishing |  WinSCP |  KFTPGrabber |  
 | SVG |  Inkscape |  
 | Documents |  
 | Office |  OpenOffice.org |  
 | Mail |  Windows Mail with Gmail IMAP |  Evolution with  Google Mail IMAP,  Calendar and Contacts |  
 | Calendar |  Windows Calendar |  
 | Contacts |  Google Contacts |  
 | Text editor |  PSPad |  Kate |  
 | Computer admin |  
 | Back-up sync |  SpiderOak |  
 | Virus protection |  avast! |  
 | Compressed folders |  7-Zip |  ? |  
 | Temperature monitoring |  SpeedFan |  ? |  
 | System Information |  (Device Manager) |  Hardinfo |  
 | Reference |  
 | Planetarium |  Stellarium |  KStars |  
 | Office stuff |  
 | BOINC |  BOINC |  
 | LEGO |  LEGO Digital Designer |  - |  
</tbody></table>