If you are using free software for audio converter and video converter then I think Blaze Media Pro Multimedia Software is the best.

Unlike other audio and video converter, Blaze Media Pro Multimedia Software is all-in-one converter, burner, audio and video editing software for all popular audio and video formats and much more in one package. Blaze Media Pro Multimedia Software can coverts the audio and video formats like MP3, WAV, WMA, OGG, AVI, MPEG-2, WMV and many more. Apart from that, Blaze Media Pro Multimedia Software also fully support data CD/DVD burning, and acts as dvd ripper to rip your dvd files and etc.

Just to summerize here are its great features:

Blaze Media Pro is a powerful all-in-one multimedia application that offers conversion, ripping, editing, recording, burning, playback, and much more. Powerful, yet easy to use audio, video, and data CD/DVD burning are all fully supported. VCD, SVCD, and DVD burning are supported. Other advanced features include video capture, video creation, combining, and extraction, video editing, copying of music CDs, audio and video merge (joining), MusicID audio recognition, lyrics search, audio tag editing, FreeDB support, and more. The audio content of video files can be extracted and saved to sound files, and frames can also be extracted to images files in batch mode. Video files can also be created from still frame images and/or other videos. Formats supported for audio conversion include CD, MP3, WAV, WMA, OGG, MPEG-4, AIFF, M4A, AAC, AC3, FLAC, and ALAC, and two-way conversions among MPEG-1, MPEG-2, AVI, WMV, ASF, Flash (SWF and FLV), iPod, PSP, 3GP, and MOV are available for video. MPEG options are available for VCD, SVCD, and DVD compliant output. DVD ripping, and audio compression functionality are also present. When converting from audio CD, track information can be dynamically downloaded from the CDDB and used to automatically name saved files. Video editing is available for AVI (uncompressed), AVI (compressed using any available codec), MPEG-1, MPEG-2, WMV, and ASF. Comprehensive video editing operations are provided (delete frame, delete selection, crop, resize, rotate, mirror, flip, trim, text overlay, adjust audio volume, etc.).

you can download the free Blaze Media Pro trial version to experience its advance multimedia capabilities and powerful features. If you satisfied with this software, you can purchase it through their website.