It depends on what you can afford, get the best computer for the price.
I had a desktop that I thought was the shit but it had some trouble with Traktor, it died on me and I wanted the best thing I could get and something that was going to last, I got a Macbook Pro and I am satisfied with it. I use it for school, net, and djing. I don't game on it, I don't download un needed music or movies or anything like that. Have a dedicated machine, that will help.