Depends on why I'm not feeling good, and how bad it is.
If allergies, and it's not bad, Xysal (samples FTW). If allergies, and bad, Benadryl (brand name only--I've tried most generics, they all suck in comparison, and one box lasts a long time).
I'll take ibuprofen (generic only), if I really need to calm down inflammation, and nothing else has worked. Most of the time, though, 70%+ chocolate works better than meds for pain and headache. I also can't use the few that do work for very long. I get immune to neproxin sodium (sp) by the 2nd dose, FI (one reason I don't bother taking it, anymore), and get a tolerance to regular old ibuprofen if I take a few days in a row (luckily, I've only needed to do that twice in my life). Aspirin does nothing for me.
If my sinuses are really bad (IE, completely blocked), I might take pseudoephedrine (the new fake stuff gives me the same side effects, but no benefits). I can't handle more than about 20mg/day, though, without getting all jittery and string-out, and never take it more than two days in a row.
Guafensin I will take with abandon, if the need arises. That stuff is awesome.