We absolutely love our Liberator Wedge. It makes a big difference in many aspects of our play. We also have the Ramp - but due to the size, its not in a place where we can access it regularly. The Ramp Wedge combo looks like a good idea - but it takes a bit more planning and we're a little too spontaneous.
We also have the Wing. It's designed to hold a dildo or vibrator. This also takes some planning to make it work - but we have found it fun the few times we've used it.