They both have their pro's and con's.
- PCs are cheaper, so you can buy a new one after a few years and you'll probably end up spending less money.
- They have more software compatible. If your college program uses a lot of software, most likely they will only run on Windows (e.g. engineering students need to use a lot of technical software, most of those programs don't support Mac OS).
- Most high-end video games are designed for Windows, assuming you have the right hardware.
- Windows usually requires updates and is more vulnerable to viruses, however Win7 has increased security compared to other Windows versions.
- If you are a computer techie you can tweak stuff in Windows
- Macs are more expensive but tend to last longer.
- MacOS is pretty much invulnerable to viruses. However, if you like to tweak computers, you won't be able to.
- Video and music editing and graphic design software are better on Mac computers, (great if you are planning on becoming a DJ or graphic designer).
- If you are a computer science major, you might like Mac better since MacOS is based on UNIX.
- Since MacOS is based on UNIX, the system is more stable.
- If you want to run Windows software you can install virtual machines to emulate Windows (Parallel Desktop, Virtual PC, CrossOver, etc), but you'll still have to buy a copy of Windows to use it.
Other than those facts, they are both computers and do pretty much the same. Don't buy one or the other because of fashion trends.