What I pack around for touring/commuting/whatever:

--- Park MTB-3 multi-tool. Can just about disassemble a bike and put it back together by the side of the road with this thing.
--- Leatherman multi-tool. Good for the pliers, cable cutter, and knife blade tools. Also kewl every now and then for the wine corkscrew ;-)
--- 6" crescent wrench. Used mostly in good Samaritan mode, sometimes there are things your standard bike multi-tool just doesn't fit, quite often on kids' and box store bikes.
--- Park patch kit, with tire levers, micro-inflator, and a handful of CO2 cartridges. Couple of spare tubes.
--- Topeak Road Morph frame pump. (Yes, I have CO2, but I'm a belt & suspenders type of guy. The number of flats you're subject to having can be mathematically defined as the sum of the spare tubes and patches/cartridges you are carrying, plus one.)
--- A Surly Jethro Tool. Just because it's cool.

Haven't had but one problem where I had to replace a spoke, but if I were out on a long, long loaded tour, I'd probably pack along a cassette lockring tool and maybe a chain whip...