I've had them all at one time or another (except for the Porsche cover). The two I like best are the Evolution IV and the Noah.
The Evolution IV is a good all weather cover. It's a big, bulky thing, so storing it will take up one whole trunk. The thing I like about that is that it's very thick, thus guarding against door dings and other impacts.
The Noah is a newer generation cover. Also for all weather applications, it is four layers, but it's very light and compact. It has a waterproof outer layer, a thin foam middle and a soft lining that protects your paint.
Neither of these covers can be washed in the washer. It ruins them. Ask me how I know.
