The contents of my bicycle saddle bag. Roughly left to right:
CO2 cartridges (16 gram threaded)
Inflator (for use with threaded CO2 cartridges)
Adjustable wrench / spanner for wheel removal
Tire levers x 2
Topeak Alien multitool
The Alien is usually overkill, but I have had opportunity to use the knife and even the chain breaker. Allen wrenches is usually all I need.
I own the chainring tool because I've actually needed it on the road, believe it or not. I don't need it anymore, though.