Will you be doing anything besides leisure stuff with your laptop? If you're in college, what is your major? What type of games do you like to play?
If money is no object, I will always say go with the Mac. I use all three main operating systems regularly, and the Mac is my favorite. Though if you're not really into one OS over another, take at look at the specs of the systems your considering. Since you're going to be playing games and watching movies I would recommend no less than 2 GB of RAM (mine has 512 MB and I can still play games, but keep in mind the systems and games are all three years old, and in the past year have started being really slow), go higher if you can afford it. Get the fastest processor that fits into your price range. If you will be storing a lot of movies/music/photos, get a large hard drive. Mine has 60GB, and that is nowhere near enough; I have to use an external. But I don't think they even sell computers with less than 100 GB anymore, so I'm not expecting that to be a huge problem. Just remember, if you buy the highest-end things right now, 3+ years down the line your laptop won't suck as much as those who cheaped out, and are now regretting it (like me).
In my major (Physics/Astronomy), I have worked with several professors on computational research. I take a bunch of computer science classes. The vast majority of scientists (that I've met) use Macs, both for their research/work and their normal/fun/everyday computing. If you do any programming, or have to use the command line a lot, you can't do better than Linux or Mac, both of which are based on Unix.
One more thing: don't get a white laptop. My white laptop is no longer white, especially the keys and trackpad. And the keyboard is especially a pain to clean, since you can't completely detach it. If you get a metal-encased laptop it will likely last longer than a plastic one, especially if you carry it with you everywhere.