I have to highly disagree with you. Orecks I think are good for what they are but they're certainly not the best for all types of floors. I'll admit that I used to at first loved Oreck then later disliked them but now I love Oreck again. Especially the ones that Oreck had contracted other companies to make for Oreck.
With that being being said. To be honest, I don't think I have a brand that I dislike. At least not anymore. I love all vacuums in general especially the ones that aren't my favorite, I would never live in a house without a vacuum cleaner. But as long as a vacuum works, I'll use it.
Poor quality, and bad cleaners. I have yet to see any of these have decent suction and airflow throughout the hose, or a brushroll that grooms well and good enough to lift deeply embedded dirt.