Best bike cover in your opinion

I've bought TWO covers since owning my bike. This second cover has died on me at only about five months. They rot and rip too quickly, is there a brand that makes a cover to last in the weather for several years? I've seen the oem cover and wonder if its really worth so much?

Awesome cover too! I had a cheapo that i ordered out of JCWhitney with elastic chords that ran through eyelets.. it was a glorified tarp that was shaped like a bike, still have it.. but would cringe at the thought of my bike outside in the elements (after owning and storing numerous bikes outside over the years)