I don't really have a "Get Home Bag" -- I have a comprehensive emergency kit bag, a "running away now" bag, and a hydration pack that I use for day hikes and outdoor range work. I guess the "running away now" bag could count as a GHB. My laptop bag is the most likely thing I'll have with me, and while most of its contents are laptop-related I do have some emergency gear in it.

• Anti-zombie machete: Way too heavy for me. I do have a nice fixed blade in my car emergency kit and my hydration pack. A water bottle is also a must.
• Monocular: Light, not bulky, inexpensive and super handy. I splurged on a nice Vortex for the car kit; the Brunton Echo is amazing for the price. Spare sunglasses are also a must for me, I keep them everywhere.
• Ham radio: Super handy to have, especially if you are with other hams or have a pair of them. Also serve well as an FM broadcast radio receiver. I stash inexpensive and fairly rugged Baofengs everywhere. The lithium ion battery packs that come with them have very low self-discharge if disconnected from the radio. Keeping the cheap earpiece that comes with it allows for radio listening with lower battery consumption. I have a nicer HT in my laptop bag. If nothing else, I can make a few contacts during a lunch break, especially if there's a repeater within range.
• Bivvy sack:An inexpensive emergency bivvy sack is way better than sleeping cold or worse if you have an unexpected night out. I prefer the S.O.L. (formerly Heatsheets) 2-person emergency blanket over everything else in that size and weight class, but I'm not against their emergency bivvy. The Lyft app is strongly preferred for anywhere there's pavement.
• While I try to avoid it, my work sometimes brings me to places that aren't so safe. I do carry a handgun everywhere that I may do so legally, and a big chunk of my "running away now" bag's weight comes from one. But I also train, a lot, with handgun. I love to read but I don't carry paperback books any more, I can read on my iPad or iPhone. I've found that as my eyes are getting older reading on a device is far easier and more enjoyable.
• I don't carry a climbing carabiner but having an inexpensive and lightweight model on the outside of a backpack is super handy.
• I do like paracord (but not 100'!) for larger kits but I have safety pins everywhere.
• MREs are enormously bulky compared to other options. I do keep a couple in my car but I don't carry them around anywhere. Cliff bars bring me joy and I will often bring them with me. If I'm planning to eat lunch on the trail or on the range I'll most commonly bring along a sandwich along with the Cliff bars.