The FatMax tape rule has a super-long "stand-out" - meaning you can stand on a ladder and stick the tape out about 11' or more to measure across the room, without having someone to hold the other end of the tape for you. Most other tapes have a stand-out about half this far.

Channel-lock pliers are often must-haves for plumbing fix-its and other things - even the occasional stubborn jar lid.

A combination square is often used to mark square cuts on smaller pieces, including most widths of book shelving. Also includes a level, which comes in handy when your 12-inch level is too big.

Necessary for any cuts to metal (this bolt's too long, etc.)

This is a great wire stripper/crimper/cutter, an essential tool for many electrical projects, big or small.

This will go a long way when you don't have a full set of sockets & a socket wrench, plus a full set of open-ended wrenches. A requirement for many basic plumbing jobs, especially on cosmetic chrome parts like shower heads.

Here's your stud finder right here, baby.

I also have this thing - you can use it with a used (cleaned up) joint compound bucket, or just go buy a new bucket from Lowes or Home Depot. It's cheaper and it holds more stuff, although you can't zip it closed. These days, I find myself using it more than my zippered bag.