It's all subjective, bikes focus on different things. I really wanted a Bianchi but the customer service reputation really put me off. Giant does a frame test every year and I tend to base much of my information off that.

It's also interesting to follow bike popularity based on what they're doing in the ProTour. I'd wager guys like Peter Sagan, Wiggins, and Cavendish have accounted for quite a bit of revenue for their brands.