The Eureka 402A Mini Light Upright Vacuum is a vacuum I've owned and used for several years. It's fairly inexpensive and ideal for a small apartment.
The Eureka 402A has modes for carpet and hard floors and is quite powerful. The power generated by this vacuum has been enough to clean up anything I've run into. It has a retractable handle to reduce storage space, and an easy-to-remove compartment for emptying out what's vacuumed up. This means no bags are needed and you can easily see when it's full. The cord is 20 feet long, so it may be a bit short if you want to vacuum two rooms at once. It's very light, around 8 lbs empty, so it's quite easy to maneuver.
The performance on the 402A can be impeded if you don't regularly clean the brushes on the bottom and a tiny compartment on the back in the bottom that captures some smaller particles. They are very easy to forget especially if you don't read the user's manual.
I did a lot of research before buying this and I still think it's the best vacuum for apartments and other small living situations -- a good, powerful, compact vacuum.