If you're looking for an easy to use video conversion tool that accepts almost any format, Aplus Video Converter might be the answer.
Aplus Video Converter has a really simple interface. On the left is a large selection of output types, or profiles, based on common formats. So there are mobile phone, iPod, iPhone, Zune, PSP, Pocket PC, Apple TV buttons and more. Choosing any of these will open a configuration window so you can tweak settings if you want, for example increasing the volume of the recording. It's not necessary to touch these, as each profile is optimized for its specific device.
Adding video files to convert is done with the + button, as unfortunately Aplus Video Converter doesn't support dragging and dropping files. The preview window is OK, but a little buggy, and temperamental about playing files. This is a little annoying, but conversion is its main function, not playback. Conversions in Aplus Video Converter are fine, and problem free, all you have to do is set a destination folder, and hit Start.
Aplus Video Converter is an easy to use and comprehensive video converter. It has some quirky visual features, but does its basic job well.