Ok, I have about a MILLION scrubs...because I spent a lot of time buying the WRONG scrubs...
There is already some sound advice in the posts above mine, but here's my opinion.
I don't care for allheart scrubs. Scrubs fit strangely, and the ones I've purchased online make me look unkempt and dumpy, not professional and intelligent. The material is not super nice, either.
Really find a type/brand that fits you best, and invest in them. You really WILL have those scrubs a long time. Buy pants that you can bend, sit, stretch, and squat in. Don't buy see-thru material. As for tops, buy LONG tops. There is nothing more unprofessional to me than a nurse whose belly button or God forbid her butt crack shows when she's (or he's!) in certain positions. Nursing requirements movement, and the scrubs should allow for that. Make sure you have LOTS of pockets, as you will need them. Urbane scrubs make cute sets, but I find the shirts are too short with only one pocket on the chest of all places. I like their pants, though.
I really like Landau's scrub tops because they fit nicely, wash nicely (with little wrinkles), and they have 4 pockets!! I never run out of room for all my nurse goodies.
And though you didn't inquire about them, shoes are very important as well. Maybe not right now while you are in school, but you will need to get good ones later on. All my friends with high arches really like Danskos (you have to sort of break them in, though). I, however, have long, narrow, FLAT feet. I have only found one shoe that I've liked, and that is a Merrill (spell?) shoe. My feet NEVER, EVER hurt...even after a 14-hour shift. That is huge for me.
Anyway, hope that helps.