Show Us The Most Beautiful Formula 1 ChassisS

Formula 1 cars will continue to evolve over time with regulation changes; this is inevitable. However, this years crop of Formula 1 cars aren't particularly pretty due to a ignorantly worded regulation. However, the aesthetics are undoubtably subjective; which brings us to the question: what is the most beautiful Formula 1 chassis ever raced?

And when I say 'most beautiful', I don't mean how fast or successful it was.

Also, show us the ugliest F1 chassis.