It's always nice to know where you can go shopping, buy new clothes and other stuff.
Giessen offers several places to indulge this passion.
Firstly, there is the pedestrian area in the city center. Allthough it's connected to few little street people usually just call it Seltersweg as for the main shopping street that leads from the Marktplatz to the Elefantenklo or short E-Klo. In December opens the christmas market every year its door and booths to people all around. Try the german Glühwein and other regional specialties.
See also: http://www.seltersweg.de/
Near the Seltersweg, recently opened, is the location of the Katharinen-Karree in the Katharinenviertel (Katharine's District).
More nice shops are located in the Bahnhofstraße. It leads from the main station, there you have a post office, along a big fitness center, a furniture outlet (with student's discount), an Aldi (German cheap supermarket), a kik, a Tedi (both really cheap shops for just any stuff), a Rossmann (drug store) and some more to the REWE in the city center.
On the opposite side of the station Oswaldsgarten is the Galerie Neustädter Tor. It's a big shopping center offering all kinds of shops, from clothes over supermarkets to book stores and more.
See also: http://www.galerie-neustaedtertor.de/
In the outskirts of Giessen in the industrial park west and in the schiffenberg valley are located a lot of hardware stores, specialist retailer for electronics, sportswear and equipment, furniture and more. What you don't find in the city center, in one of those place you will find it for sure. If for furniture or decoration you prefer IKEA, there is one still under construction in Wetzlar. Another one a bit further away is in Frankfurt in the industrial park of Nieder-Eschbach.