Buying every software is impossible. I would be broke if I do. So using open source software is most viable and economic idea.
Here are the some of open source software that I use and think others should also try there hand.
I call the OpenOffice.org as the alternate for the commercial Microsoft office package. It is full-featured office productivity suite, consisting word processing, spreadsheet, presentation, drawing, and database functions. It even offers import / export feature from Microsoft office allowing data exchange
When I first encountered 7-Zip, I mistake it for another version of winzip. From the start I liked 7-Zip. It incorporates a wide range of decompression formats and its own advanced LZMA-based compression engine, 7-Zip delivers performance on par with proprietary formats like RAR and ACE while remaining entirely open and extensible.
3. VLC Media Player
Only recently I started to use VLC for every purpose. But it’s giving me all satisfaction that other probably can’t! It can play almost all media, they say, I believe it.
I may not use virtual box every time but it is powerful product which is rich in feature, high performance and most importantly free. VirtualBox runs on Windows, Linux, Macintosh and OpenSolaris hosts and supports a large number of guest operating systems. It is great tool when need to have multiple of OS in a single system.