Everyone’s needs are different, but I would have to say Climber and (now discontinued) Squirt P4. The Climber is then the primary tool, but the Squirt fills in a few gaps, including file, pliers, and wire cutters. And the P4’s excellent selection of screwdrivers, while rather short by conventional standards, are often long enough to access the recessed screws that can be impossible to reach with the tip of the Climber’s can opener.
All this in a combo that remains very pocketable.