What I do, for quickest performance, is configure my Macintosh to launch Image Capture when it sees a memory card. Image Capture is a tiny utility that comes with every Mac and with Mac OS X. I configured it to automatically download everything, and after it's done, it launches an AppleScript that umounts the card automatically. So just put the card in, wait for the download, and pull the card out.
Later on, I use Aperture to move the files from that directory into its own library.
So, no third-party software is necessary, and if you chose to use iPhoto to download the card directly, that's not third-party software; included with every Macintosh as mentioned above.
One feature that I believe doesn't exist with Windows in any version is Finder previews with RAW files. Since RAW decoding is handled within OSX (Aperture and iPhoto use this capability), Finder previews work even for RAW files. My understanding is that you do need a third-party application to do this (correct me if I'm wrong) in Windows.
OSX RAW decoding handles the Canon 5D.
EDIT: Since you used the word "intuitive," and I didn't remember how my computer was configured when I got it, I just plugged my 350D's memory card with some photos on it into my daughter's MacBook which has never seen a camera's memory card before, to see what happens by default. What happened was that the memory card showed up on the desktop, and then iPhoto launched automatically. It brought up its Import screen which has an Import button clearly shown. I would judge this to be about as intuitive as it can get with today's technology.
May I ask why you have this question? Might be helpful to focus our answers better.