Videomaker – Learn video production and editing, camera reviews › Forums › General › Video and Film Discussion › HD avi video failed to convert on YouTube,what to do? › From what I heard, YouTube
From what I heard, YouTube supports virtually every existing video file format. Youtube may not approve of nearly uncompressed video, so that bandwidth (and/or server space) is not wasted.
Personally, I would use MPEG-2 or AVC MP4 if possible as your export format.