Must Have Linux apps / applications / software

This is the List of Must have Linux apps for the normal desktop users. These are the apps so famous/useful that you can find these apps easily in your Distro's Repository. Doesn't matter whether you are on a rpm based distro or debian based distro or you are on a Gentoo Distro.
Comment any remaining app if you think that should be in this List
1. p7zip           {7zip for the Linux}
2. k3b              {CD/DVD Burner}
3. chromium-browser {Open source version of Google-Chrome}
4. pdfsam         {extract /merge pdf file}
5. pdfchain       {modify/edit pdf files}
6. kget             {Download manager}
7. gparted        {Partition Manager}
8. virtualbox
9. multiget        {Download manager}
10. ktouch        {keyboard typing learning}
11. krusader     {equivalent to winscp may be considered as replacement of filezilla}
12. vlc               {Do I need Explain this}
13. empathy      {integrate your facebook,gmail,yahoo chat in single app}
14. calibre         { it is library management tool for the ebooks supporting various formats like -mobi and pub}
15. youtube-dl   { Download youtube videos from your terminal, very easy to use }
16. banshee        {My personal music player }
                                                                .....list to be continued....
install above in one go...
sudo apt-get install  p7zip k3b chromium-browser pdfsam  pdfchain  youtube-dl calibre vlc  krusader kget multiget banshee