Panasonic MC-V5504 Vacuum Cleaner
An older design, perhaps, but a great example of an enduring and proven concept. This cleaner is intended to deal solely with carpets, and by all reports it does so admirably, despite its lack of bells and whistles.
While it is marketed as a commercial cleaner, with its wide cleaning path (12 inches) the MC-V5504 can also be used to good effect at home. The extra-long power cord means it is not necessary to unplug it for every different room.
Its bypass system prevents damage to the motor caused by objects getting caught up in the blades. All in all an effective cleaner, testified to by the glowing reports provided by various users.
As part of its classic design concept, the machine uses a replaceable bag system. Before purchasing, it would be worth checking availability and cost of replacements.