There are two best places: 1. Shenzhou Building near the train station, which specializes in selling computers. 2. Taishan Digital Plaza is newly opened. I have been there once. It is not bad and has a complete range of things. It is the original one.

Hualian Commercial Building, if you ask around, you will know Hualian. The others are large shopping malls that sell everything, but they are not as popular as these two places. They feel more professional.