Conspicuously missing from this thread, up until that last post is the Ventus. I think if you look at WGC statistics you will see that the Ventus has more wins than the 20.

I had a 20 in the 90's, nice ship, great flaps and a joy to fly. I then moved to an LS6b, it was nicer to fly than the 20 and closer to ASW-27 performance than was the 20. The LS was better coordinated with a higher roll rate than the 20. It did take me some time to learn the feel of the LS6's stiff carbon wing after years of flying the floppy 20 wings.

So , while I might not call the 20 "the greatest", it certainly was one of the great gliders of its day and has provided thousands of hours of enjoyment to pilots world-wide.