VLC Media Player is an excellent choice for an extremely versatile media player, and now it is also available as a portable application from PortableApps.
There isn't much point going into exactly what this program does (see our VLC Media Player review), but much more about where you can bring this version. It allows you to easily run a media player from portable media such as USB thumbdrives and even memory cards.
Highly recommended if you need an easy way to play media when you're not at your own PC or if you're reluctant to install it permanently.
Version 3.0.4 is a freeware program which does not have restrictions and it's free so it doesn't cost anything.
Virus and Malware Tests: The program has been tested with several antivirus applications and has tested clean of viruses, malware or trojans.