The bell curve of sGPA's for admitted students seems to peak around 3.5... closer to 3.7 for the fancy schools, down to 3.2 for the not so fancy schools.
I see in the ADEA guide some schools specifically mention that they take into account the heaviness of your course load. It doesn't change your grades, of course, but they like to see it.
For what it's worth... I took Organic 2, Biology 2, Biochem, Physics 1, and was a teaching intern for Organic Lab 1.... all last semester... while volunteering as an ESL tutor and volunteering at dental clinics on the weekend. Straight A's. Yes I'm bragging. No, I don't see much of my friends at this point in my life.
I'm going to go to Chipotle now to drown my loneliness with high levels of cheese and sodium.