I gave a similar response in a travel question a week or so ago. Standard disclaimers apply, and please forgive my spelling of various drugs:

I carry Ibuprophen for gneral aches and pains. It works for me, as well as working as a good fever reducer and anti-inflamatory. I also like that the toxic dose is significantly higher than the theraputic dose. If I get confused and take an extra dose too soon it is unlikely to cause me great harm. Too much acetomenophen scares me.

I use Aleve/naproxin too, but I find it less useful. I made the mistake of taking it on an empty stomache once, and it's not something I'll ever do again. Not a problem with ibuprophen. That said, when my back is really messed up, the 12-hour dosing sure is convenient. For heavy duty pain, I keep some legally perscribed percocet in my kits.

Benedryl has way too many uses not to bring it along. Aside from being great for allergies, it is useful as a sleeping pill and to prevent motion sickness.

I guess if you really need it, immodium does the trick reasonably well, but the few times I've used it, it's been really unpleasant. I do find pepto bismol chewables to be useful and not terribly unpleasant to take.

I've got little experience with the others. One word of warning - if you get sudden pain in a joint, especially around your big toe, stay away from the aspirin. I recently discovered I'm prone to gout, and aspirin makes it much worse. Another mistake I will not be repeating.