Talking of Dawes, I don't see how you can have a worst mountain bike poll without including them.
When I was thirteen, I saved up a year's worth of pocket money, sold my Peugeot Ranger 'mountain bike' (that was another 45lbs of non-stopping horror) and took my parents to the local bike shop to sort out my birthday present. We agreed that I would be getting one of the new, yellow, Specialized Rockhoppers with the U-brake under the chainstay. I was so happy.
Come the big day, I wake up hugely excited, run into the living room. There's a large gift-wrapped package in the corner. I wait for my parents to get up. My excitement builds. They get up. I start to tear at the wrapping paper. IT'S A ******* DAWES!!!!
They bought it because it was the same colour as the Rockhopper and a bit cheaper. I didn't say anything - just offered a weak smile.
Call me petulant, but I hated that bike.