One of the first things I did when I got my new MacBook Pro was replace the hard drive with a larger, faster drive. I ended up with a Seagate 7200.4 500 GB (ST9500420AS). I hadn't had any problems with it, and it got hit pretty hard throughout the course of a week. I partitioned it as ~427 GB for Mac OS X and ~72 GB for Windows 7 Pro. The Windows 7 install is primarily for gaming, with some Windows 7 cross platform testing thrown in.