That’s a little tough. The one that comes to mind is the Pearl Izumi Amfib Tight ($99). It puts a proprietary Pearl Izumi waterproof/breathable fabric on the right front, with breathable fleece on the back. The idea, of course, is that when you’re running or cycling, water, snow, and so on will mainly hit the front of your legs. The down side to these tights is that they are REALLY WARM. In most cases, it would have to be below freezing before I’d even consider putting them on. Terry also makes a tight called the Dolomite ($70) that’s very nearly waterproof, but also very breathable. Might be a good choice.
Beyond that, you’re looking at some sort of pullover pants. Gore-Tex, for instance, is marketing some pants made of Windstopper (similar to Activent) under the Concurve brand for $99, and probably worth a look. Otherwise, the only good choices are expensive ones, such as Cloudveil’s Symmetry Pant, which uses a Schoeller fabric that is highly water-resistant, nearly wind-proof, and dries very fast. Alas, they’re $225.
From there, you get into full Gore-Tex pants. Best bet here is to buy a pair from the biking-gear makers, such as Performance. You can get a very nice Gore-Tex pant from them, the Elite Cycling Pant, for $149. It’s even on sale now for $99.