Old saying about carry guns.. "One is none, two is one."
When I'm working, it's usually a Glock 20 IWB, Glock 29 elsewhere with a +2 mag and 2-3 extra 15rd magazines but there's only a handful of folks out there who can switch a mag faster than a New York reload. Usually tuck a Ruger LCP with one reload in my clothing or vest as well.
1-2 knives, usually one fixed (fighter) one assisted-opening folder (utility, backup). Impact device(s) such as a Comtech Stinger, Kubotan, etc. in various locations. 9P or G2 flashlight. 1-2 sets of Peerless 700s or 801s. Sometimes other various items (ASP, OC, etc.).
Might be swapping out for a Springer 1911 Pro and Kobra Carry at some point, haven't made the leap yet.
Oh, and don't forget the Raybans or Oaks with a skinnie tie. Completes the look.
edit: Honestly the only heavy parts of my kit are the extra mags. The guns are fairly light being polymer frame. The knives are light and spread around. The G2 is a light, powerful torch. A set of Peerless 801s can be tucked anywhere. Fully loaded I can bang out a sub-7min mile and a sub-60 second 400m, and I know guys who can load more gear and destroy my times.