I always carry a flashlight, tire pressure gauge and tire kit. Longer trips I carry a leatherman type tool, folding allen and torx wrenches, channel locks, vise grips, wire butt connectors, fuses, 1/4 drive sockets/ratchet/ and extensions, screwdrivers, rubber gloves, oil filter, and chain lube. I think that's about it. You wouldn't believe how many times some of this stuff got used, either by myself or on someone else's bike.
