Multitool --- Victronix SAK - Climber model (I think), far and away the handiest knife I own. Used to carry a Leatherman PST, as well as a Super Tool, but I got tired of lugging it around....if I need pliers I'll bring my toolbox).
Folder --- CRKT Large KFF, Point Guard or small KFF (depending on whether I'm dressed casually in jeans or wearing a coat and tie to work).
Fixed Blade --- CRKT Stiff KISS as a neck knife. I'm going in a different direction, assuming that we're talking about actually carrying all of these. I look at the fixed blade as a potential backup to the folder. Toting a CS Recon Tanto (my favorite fixed) would quickly force a change in employment, as well as career.