I re-opened this thread from last year because I'm looking for a new raincoat for the upcoming season. Anyhow, I saw this post of Andrew Skurka's that Oregon Mouse passed along: interesting, and he pretty much says what I have come to believe, which is that you're either going to get wet from sweat or from rain (or both) and you're never really truly going to be dry if you backpack in the rain. You have a little better chance if the jacket is new, but the fancy "waterproof-breathable" finishes are pretty much over-rated and have never lasted that long on every jacket I've ever owned. I've been using Marmot Pre-cips in recent years, and I like them ok, probably will get another, but I don't expect to be truly dry if it rains much, the best I can hope for are dry clothes for tonight and a sunny day tomorrow, and I strike out at that, too, sometimes.
No, I think the best rain gear is keeping a stiff upper lip.