I'm definitely not interested in a between-trilogies game. We've already had two extremely crappy The Force Unleashed games in that period and, well, the "crappy" part says it all.
One of the things I liked about the first KoTOR game was the setting. Everything looked different, but still quite familiar and still Star Wars, so I'm more interested in a game set either long before the movies, or long after them, as those periods allow for more creative freedom, both visual and otherwise. Of course, Jedi Knight 3 is a must (I consider Jedi Academy to be a stand-alone expansion to Jedi Outcast), regardless of anything else.