I noticed you listed a complete socket set (both metric and sae!) and even vise grips.
Good man!

But Ironraven points out something I've been thinking about for a while.
What about vehicle specific expendable parts for the vehicle?
I carry a full set of spare bulbs and fuses just for starters. These are items that receive massive markups at convenience stores and few quickie marts have a wide selection of good quality headlight bulbs. Usually that stuff is overpriced junk.

But I also carry an oil filter, drain plug, drain plug gasket, spark plugs, and a fuel filter.
Fortunately my vehicle does not use a serpentine belt but I carry a timing belt, t-belt tensioner bearing and a water pump/alternator belt.
Does this seem excessive?

My thought process is to reduce down time should I be forced to take the car to a mechanic in some locale that may not have quick access to parts like this which can be very vehicle specific. Haven't we all heard tales of someone we know being stuck somewhere, far from home, while the mechanic is "waiting for parts"? Not to mention the parts markup when they know you stuck there and have no choice...
Thoughts?