Earlier thread asked about most often used tolls (stationary, as it happens).
Different question. What tool do you just like to use? Be it a kick, or a zen experience, it's the one you just look for an excuse to grab.
For me, it's an old 603C (type 2) with a Hock blade. Something about the size, balance, and the whispers it makes on wood, just makes me grab it any chance I get. I even misuse it, when a larger or smaller plane would be more appropriate. Heck, I used it to flatten and smooth the top of an old Sjoberg bench I picked up at a garage sale! Coulda used the 607C, but that beast is big, heavy, and ugly and the 608 is just uglier.
Maybe I'll just dump all the rest of the planes rather than let them sit, unused, in my plane hanger (that's what I call the shelf they live on).
Tom