I have a collection of saddles, some better than others. The one that works the best for me is a Brooks B17. It's not perfect, but close. After 40 miles my butt can start to get sore. I find that if I get off the bike for 10-20, my butt has recovered and I'm comfortable for another hour or so. Standing up for a couple of minutes while riding also helps.

On tour my butt still gets sore, pretty much every day, but I just get off the bike for awhile. I don't make as much progress as someone who sucks it up and keeps riding hour after hour, but I'm not in that much of a hurry and I like breaks.