I beg to differ with how well the Terry Knickers fare on long rides. I have tried them out on one 60 mile ride a while back and had some difficulties with chaffing. They are great for shorter 20-30 mile rides, but I wouldn't trust them for anything much longer. I love my Pearl Izumi's (with the Pressure Relief Chamois-PRT) and my Briko's (found them on sale for about 1/2 off -otherwise they are quite pricey! They are my favorite though!!) Both of those brands have treated me well on many longer rides.
I think this topic is just like much in cycling--it depends on the individual as to tastes and preferences. You find what you like by trial and error (which I know can be expensive, so asking for advice is a good start.)
I have never tried the Chamois But'tr (or whatever it's called) and am wondering what people have to say about that. From the name, it sounds like it'd be greasy or something. I am doing a 6 day 500 mile ride and think that by the end no matter what shorts I wear I will be hurting a bit. Am wondering if this might be something worth trying to cut down on at least some of the discomfort. Any thoughts?