I carry the OEM tool kit, a tire plug kit, compressor, one spare spark plug, and some wire ties.
It's hard to tell what you're really going to need without a good crystal ball

It seems there are a lot of alternators that go bad. Mine died at 35,000 miles. They go out without any warning so you can expect to get stuck if that happens. Here's a site for good rebuilt alternators:
http://mysite.verizon.net/resp3jbj/I carry the extra spark plug now because I had one foul the day after a 1,000 mile ride.
Most of the time my tools get borrowed by Harley owners that ride with me
