I carry just about everything I think I would need to change a battery, spark plugs, or pull the seat and tank off with. I also carry some electrical tape and zip-ties, a flash light, cell phone, and sundry other items.
The only time in nearly 40k miles I have ever had to use any of these things is working on my bike in my own driveway. Even then I have other tools I use in combination out of a larger tool box. Just routine maintenance, a couple of rejets after changing the pipes, etc. - these things don't break on the road!
