Miele!
My mother's Miele s230i that was purchased in October of 1985 is still hands-down the most powerful vacuum cleaner I've ever encountered. The motor was rebuilt in 1996, and when it has a new bag in it and the pre-motor filter has been cleaned and/or changed, that thing literally pulls the carpet up, and she doesn't have a power nozzle. (Sometimes I think the ridiculously powerful suction might be a bad thing, though. Last time I used her vacuum and I checked the bag, it seemed like the "dirt" was nothing but carpet fibers...and she doesn't even have a new rug.)
In fact, when I vacuum the guest room where I stay when I visit mom, I have to use the suction relief to tone down the suction so I can pass the nozzle over the rug, because the suction is so strong.
