Some of my favorite maybe not unsung, but "seldom sung" models:
The SuperLeaf was mentioned and pictured a couple of times, but it can use more ink :) It is spec'ed very similar to the Manix2, but has a different feel. They are still available in some B&M stores at reasonable prices and turn up in the aftermarket from time to time. I love the smooth action, the inertia of the heavy 4mm blade which can swing in or out slowly with an authoritative thunk, and the discrete deep carry wire clip. Also, it's turning me into a compression lock liker. Another thing I like about the design is that the spine jimping is almost flush with the liners, which makes it very smooth and comfortable when you don't need it, but when you do need it and press firmly with your thumb, it can be plenty aggressive. I also like the VG-10 steel but would love to see a sprint in another metal.
I think the R model, here in Nishijin, was mentioned but not pictured. It's one of my favorites, halfway between a Delica and an Endura, but with a nice choil. It can be a more dressy alternative to the Stretch, and I'd really love to see it occasionally included in the FRN sprint series. (Shown w/non-standard deep clip which I tried briefly but went back to the original)
I didn't see any mention or pictures of the D'Allara Rescue (pictured here) or the D'Allara Drop Point. These knives have, as far as I know, the most comfortable, contoured and hand-filling handle of any spydie folders. This is a great feature to prevent blisters or hot spots in very hard or long cutting, which could be encountered in a rescue situation. I use the Rescue model to cut limbs up to an inch and a half, which can frequently be done with one stroke if you put a little pressure on the branch with the other hand
I'm on the lookout for the drop point model and eagerly awaiting the new model Sal has mentioned.