I guess you're asking about video editing software? I don't know specifically about mac as I'm a PC user, but I think most options out there are pretty platform independent. EDIT: Gee, I just poked around a little bit and I guess these do tend to be platform depend, so I guess you've had to run using Parallels or something.
I've been quite happy with Sony Vegas. I use the Movie Studio version because the full version is outrageously expensive (as is true for all of the pro editing software). The Pro version surely does anything you'd ever want to do.
I miss a few features in the stripped down version, but not too much. It lacks templates that you can download to make cool prefabricated sequences, but it does have a core set of media generators that it comes with. It doesn't do "envelopes" on slow motion/fast motion, which I'd find useful. It also has a max value for fast motion, so if you want to do a time lapse you generally have to take it the max, render the video, and then apply fast motion again.
But 99% of the features are there and it's very intuitive. I've never used other popular programs, but have never been inclined to try since Vegas seems to do what I need efficiently. I suspect it's largely just getting familiar with a particular interface.