brown goat skin
This is the industry standard saxophone pad. There are many choices, as there are many manufacturers each offering a number of different styles and configurations. The pad I keep in stock has a medium firm felt and a brown natural leather skin that is not as sticky as some of the "beauty/Italian shoe leather pads" used by horn manufacturers.

white kangaroo skin
This pad has a number of features. They are fairly thin and quite firm, they respond quickly and crisply. They are also the least likely to stick to the tone hole. Another very nice quality is the durability of kangaroo leather. It can't be matched! These pads do not tear and last a very long time. Cost is about 1/3 more than the brown leather pad.