I would recommend
VLC MediaPlayer as it plays
almost all .mov files.
In case it doesn't play the files you have, there is another player
mPlayer that most likely will play them.
Links to download sites etc. are found here:
CODECs list for Movies/Alternate players / Video help forums/ video-mp3 fixers - Link
In case none of these work for the file(s) then it/they are most likely corrupt, and you would be better off deleting them.