RockPlayer - RockPlayer is a video player that supports nearly all formats.
VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
MX Player - Powerful video player with advanced hardware acceleration and subtitle support.
Vanilla Music - Vanilla Music is a clean, simple and opensource music player for Android.
Emit - Emit can stream from a Windows/Mac/Linux machine to an android/iOS device.
MoboPlayer - MoboPlayer is a video player for Android that plays most video formats.