circa 1994-95 I happened into a store where they were having a huge sale on cycling clothing and I bought a ton of stuff, including something I'd never seen before: Descente padded cycling underwear for 5 bucks a pair. What a revelation! From that point forward I've never ridden any considerable distance without padded cycling underwear (called liners now I guess? At least my Novarra ones come in boxes that call them that) AND padded cycling shorts. I also own Brooks Saddles and a Fizik Arione Saddle(both great), but neither of them see my butt for very long without padded cycling shorts or bibs AND padded underwear. The one who really loses out on this deal is my wife, who launders all the shorts/undershorts I go through in a week.

Cold and cool weather tip: Patagonia or equivalent tights/base layers in between the underwear and the shorts. Works great