West Coast's, for a couple of reasons. Firstly, putting yellow next to white has, since the days of heraldic charges, long been regarded a aesthetically displeasurable. Secondly, I've always been a traditionalist and I therefore like plain, simple designs - that stylised Eagle in the shape of the WA coast is not plain and simple.
Hawthorn's mixture of colours is terrible. I'm not sure whether it was a home or an away jumper, but the Bulldogs sported that truly awful guernsey in about 1998-99 with the bulldog head inside a red and white diamond-like shape. If that was a home strip, that was the worst ever.
Why do people always criticise the Carlton M&Ms guernsey, yet forget about the time the Kangaroos wore orange and white stripes against Collingwood, which was significantly worse?