Hey Lenny, nice idea for a contest; thanks for the opportunity.
My most-carried slipjoint is likely my 2009 BFC stag barlow. The D2 steel is just the best I've ever tried, the handle covers are good looking, the build quality, well... Queen did a bang-up job on this one! And, between the clip blade and the wharncliffe, there's not much this one can't do.
Favorite cover material is a nice, dark, jigged bone, dyed some sort of warm color (a red, orange, brown, something like that).
My favorite blade shape, just for its appearance, is a spear point. I like the symmetry of it, and find it just as handy as a clip blade. After all, most clip blades are just spearpoints with a chunk taken out of the top...

And finally, I use it for just about anything that needs to be cut. In my work, I have lots of uses for a pocket knife: stripping wires, cutting insulation and tape and the like, trimming bits of wood and plastic to fine-tune the surrounding area when I install a new piece of gear, making my lunch during the work day... You name it!
Here's the barlow in question, in case anyone doesn't know what it looks like.