I have one of these small 120V fridges, too. Mine works well. It is some Asian brand bought from Target. A lot of these small 120V dorm fridges have the cooling coils in the wall sections rather than the rear like a typical 120V fridge. Make sure you have some ventilation around the outside of the fridge. If you do have adequate ventilation, it may be time for a replacement. A fridge full of food and frozen stuff can have more value in the food than the cost of a replacement.
If you have a big budget, the small 12V compressor freezers and fridges are easy to power and are built better than their 120V counterparts.