If you have the cash Arcertryx is awesome but very expensive. My main jacket these days is an Outdoor Research Foray, about half the price, which uses GoreTex PacLite and has full length zip ups. Have stayed dry through several days of heavy rain/snow/wind. Biggest problem I face is getting wet from the inside out while trudging up a mountain. This jacket comes the closest of any i've owned to allowing you to stay dry both inside and out.
