I don't know which one you are, a hacker, gamer or student. Or a mixture or them. I would suggest to get a solution that will solve all problem in a mix. And that is save up and get yourself a nice good laptop. With good specs, you will be able to game on it. If it is the screen size then you can always hook it up to a larger screen just for gaming
In college, you sometimes need to present you work in class or to your lecturer so you need to travel with a machine you are familiar with to do that.
For hacking adventures, i don't think you will go pwning wifi or go to a conference, think defcon, with your desktop. So i sooo dearly think a laptop will fit all the needs here.