One rock mold to rule them all!
There are many rubber Woodland Scenics rock molds out there, but for me, this is the absolute best one. A great combination of flat area and depth, it looks great with almost any side (except the flat back of course) pointing up. I have used it in about 3 places on my layout and the pattern is so random, you really can't tell. The flat surface on top makes for a great place to add more smaller hydrocal rocks and grass, to give it a 'been there a long time look'. Works very well with Preiser's mountain climber set in HO.