I'm sure that plenty of people have asked this question... But I cannot find a current, definitive answer.
A college student, majoring in anything to do with computers will generally be doing one of three things on their computer:

1. Productivity software - Microsoft Office programs, a compiler for whatever language they're teaching, etc.
2. Graphic programs - Photoshop, Flash, and Illustrator in my case.
3. Gaming. In my case, I stick to mid-end games. The games I play require around a Pentium 2.4, and a basic video card.

So, all I'm wondering is if I am looking to replace my desktop, so I can spend as little time at home as possible, what are the bare minimums I need to start with? Can I just use a Core 2 Duo/Quad, or do I need to step up to an i3? I really don't know anything about AMD, so i wouldn't know about their comparable models.

The processor is the big question here. Any laptop I can get will have 2-4gb of ram, which should be enough, and I'll probably use an external hard drive, so I can work between computers anyway.