My favourite tools would be -
Handy... a metric "dog bone wrench" I picked up in a TSC special offer bin a while back. It has 10mm up to 18mm all in one tool with a swivelling head on each end. It is a handy tool to have in the toolbox.
Useful.... Sears baseball hat with white leds on the front peak. This is one of the best items i have for those late evenings, trying to get the last out of the daylight. For close quarters work, this is a real useful hat to be wearing.
Wouldnt be without... Craftsman "80 years special edition" pocket knife. The stainless steel one with black handle. The one that uses standard stanley blades. I cannot go out working without that tool clipped to my belt, I always use it.
Safety in mind... Fluke volt alert probe. Tells you when theres power in that cable without having to find bare metal.
Right tool for the right job?... I have a half dozen surgical clamps I picked up someplace that I have found to be really useful from time to time. For clamping off tubes mainly. From jobs such as removing motorcycle fuel tanks or clamping off rubber brake lines, these little surgical clamps have been really handy. Also, I've used them for offering up tiny stainless steel screws (non magnetic) into akward places, they make for a firm grip on the screw head to run in a few threads before you can get a screwdriver on..
Travelling companion... Swiss army knife. My folks bought me a big ol swiss army knife for my 21st birthday (long...long time ago). I bring it with me every time I travel. Very handy tool to have in your suit case for light hotel room duties.