Would a stereo or mono shotgun mike produce the best overall sound quality on a camcorder?

I'm taping interviews and crowd scenes as well as ambient nature sounds for possible broadcast and DVD release.

I'd go a stereo. If you have it in the right position, both Channels will pick up the main sound (eg. the interviewee) but also provide more realistic ambient sounds. I dont kno which ones better but make sure that u hav it on the right setting when you film or otherwise you can find urself recording all the sound around you and not the person speaking or a specific spot and not all the sounds.

learnt about that the hard way. You have to go with the best microphone for each job. You have a few jobs, each of which needs a specific type of microphone. For interviews, a wireless lavalier works best followed by a wireless hand held. For crowd scenes and your nature shooting, a stereo shot gun on a boom might be your best bet.