Rapha's Loopback Trouser is perfect for anything. Dress it up or dress it down, the pants have a cut that's perfectly suitable for any situation and the DWR weather-resistant coating will keep you nice and dry. The fabric of the pant is made from Pertex, a lightweight, ultra-durable material that is cut in a relaxed fit yet has a taper to not only give it a great shape, but also makes it more comfortable when you're active or on the bike. 

$170, Rapha