Selle An-Atomica Titanico.

Leather is pliable and waterproof, so it requires no break-in period or treatments, unlike a Brooks. I'd only used plastic and foam seat before I started touring and found that they were good if I was doing less than 50 miles a day. Now I can ride centuries day after day after day on the Selle An-Atomica. Also, I have several inches of saddle to bar drop on my touring bike and find the An-Atomica works well if I have it nose down a smidge.