If open-source freeware has a weak spot, it's the hobbyist thing, and nowhere is that more evident than in media players. "Wait while it updates what? Font cache? I just want to hear 'Surfin' Bird!'" Many people are more than willing to forgo the advantages of open-source players for something easier to use.
MPlayer is an open-source media player optimized for playing movies, but it has a lot of options and capabilities, with more coming all the time. SMPlayer aims to be a unified front end for MPlayer, simplifying access to basic features such as playing videos and DVDs while still enabling advanced features like filters. We recently tried SMPlayer Portable, a fully portable version of SMPlayer.
"Portable" in this case means the program will run from any Windows directory without having to be installed or making changes to the registry, including from USB drives and other portable devices. However, the download unpacks much more than just the program's executable file, including text documents and media files. If your extraction tool or method doesn't create a folder for SMPlayer Portable, we recommend creating it yourself and extracting the download's contents to it, and then creating a desktop shortcut to the executable for easy access. If that already sounds too fiddly, you might have a point, but it's worth sticking with.
As for SMPlayer Portable's performance, it's essentially identical to the installed version, and they share the same interface, a well-rendered player window with basic controls along the bottom and many more features and options in a toolbar along the top of the window. And, as is the case with SMPlayer and MPlayer, it did a terrific job of rendering our videos, too. We could open files, DVDs that were in our drive tray or copied to a folder, and URLs. Large buttons gave us quick access to Audio and Subtitle controls. SMPlayer succeeds in its goal of providing an easy-to-use front end that doesn't compromise MPlayer's capabilities.