Well, if you asked "laptop or ipad or galaxy tab", I would answer "laptop" without hesitation; you need a real keyboard to take notes and write papers (yeah, you can get an external keyboard for some tablets, but that's a hassle), also if any of your classes require using software, that software is more likely to run on a laptop than a tablet.
But if you really want a tablet, of those two, I think iPad is the better choice, because it has more apps (though in a year I have a feeling the Android tablets like galaxy tab will have caught up a lot).