If you need proper advice, this is one of the best computer shops to go to. Not necessarily the cheapest, but they carry a wide range of products. Their webshop is convenient as you can check availability if you have a specific product in mind — which will save you the trip when they’re out of popular products like colorful external harddrives! The downside is that it’s often busy, and people take their time once they’ve had to wait for their turn for a while. They also have a shop on Kinkerstraat.