Well, I have to admit that I'm behind the times. I don't really have a “favorite” KBSC but that's because I probably work a bit differently than most of you gurus. I rely instead on a piece of hardware (Xkeys Professional) and a piece of software (MacroExpress) to handle all my shortcuts (other than the very common, universal ones like Copy and Paste). I've been using this combination for years, probably at least 10 years, and couldn't be happier.
What I like best is that MacroExpress lets me create “keyboards” for each of my programs, with macro functions or calling of a script assignable to a single key combination. XKeys lets me assign a specific key combination to a single button. Confused? Well, I'm not doing a very good job of explaining this so let me try it this way, using MS Word as an example (it works the same with InDesign, Photoshop, and other programs).
I use a macro when editing in MS Word that I call a Toggle macro. (The Toggle macro is part of the EditTools macro set for editors.) The macro lets me “toggle” from “1” to “one” or “ACT” to “American Council of Techology” or to/from almost anything I want, including changing “alpha” to the Greek letter alpha (it comes with an editor so I can add or delete what I want for future use). However, there are limits to the number of keyboard assignments one can make and still keep handy all of a programs functionality, so I use the more difficult key combinations for these kinds of macros. Thus I assigned Toggle to the keyboard combination Ctrl+Alt+Shift+M. But rather than having to press that key combination (or even remember it), I assigned a button on XKeys to trigger that key combination.
With InDesign, I assign keyboard combinations to things that I normally do to such long key combinations and then use my XKeys to activate it. It also lets me group similar functions across programs, thus I can use the same buttons for tables in all programs (or most programs) and thus not have to try to remember what the key combination was in program A and what it was in program B.