Well, to go against what most everyone else is saying, I strongly recommend DivX, *OR* the newer XVid.

You said that you wanted ok compression on a format that just about anyone can play. Well, aside from the people here that seemed to have trouble with is, 99% of "downloadable" "home videos" are Divx / Xvid. You can control the bitrate to a T to make it fit on a CD or DVD or just for your HD..
I do encoding for a fansubber (ack, yes. Anime. Don't hate me now.) every so often, and while it isn't fast, I get really good video out of it..
(Personally, I hate anything QT. Everything I've seen is either bad quality, or the player sucks and ruins it..) Also, I'm NOT on a Mac, so..

Me.