For strictly day trips:
Tylenol
Motrin
Benadryl

Everything else can wait til I get home.

And, if I can get on my soapbox for a minute... aspirin. It is NOT a miracle, cure-all drug. Sure, it's light and cheap, so fine, if you want to carry it, go ahead. But don't think that popping an aspirin will stop a heart attack cold in its tracks. Ask ANYONE that's been treated for a heart attack - you don't get an aspirin and the staff walks away. It stops platelet aggregation, ie, clots. It doesn't break down the clot that's already there, it doesn't relieve spasm of blood vessels, it doesn't make your heart return to it's normal function. Yeah, sure, you may decrease some of the damage of a heart attack, but it's still going to be happening.

Bottom line - if you get a heart attack in the woods, you're going to make it out, or you're going to die. A few aspirin isn't going to do as much as a lot of people seem to think.