or you can also get VLC which is what i use, i can play pretty much any video file on it, the best media player IMO...if you use messenger alot, ol, msn, yahoo or any of those i d probably recommend you to get Adium or Mercury, you can open all you accounts at once, they are both great, adium has no video support though but i think mercury does. If you like safari then you are set for your browser, if you are not liking it so much try Firefox it"s what i use and I love it. Set up your mail accounts with mail it works great for me even with my hotmail account.
torrent client..i use azureus but transmission is also a very light and great one. your music what s up with your music? it took me days to gte my music in my comp...anyways have fun, congrat and enjoy your mac.
I used to use VLC before finding Perian. After Perian I started using Quicktime more but still used VLC for full screen. Quicktime now has full screen, so I have VLC just in case Flip4Mac and Perian can't do the job with Quicktime.
I second the use of Adium. Besides having multiple accounts, it is highly customizable so it will look the way you want it to.
I recommend Firefox as a backup browser for when Safari doesn't work, but not the Firefox Firefox. Use this version called Bon Echo. It is EXACTLY the same as Firefox except it will run a little faster and use less system resources because it has been optimized for the Intel Mac. Download it here.