As an undergrad many years ago... Advanced General Chemistry. According to the pre-med advisor at that school (when I spoke with him in April '06), "Oh you must have been in one of the last groups to take that class, because we realized it was a really bad idea.."
It was both semesters of General Chem smashed into one semester, so you had class 5 days/week and lab 4 days/week for a grand total of- 5 credit hours. (If you were applying to any other med school, the committee apparently had to write you letter saying this "counted" as 2 semesters of Gen Chem.) On the invitation to take the class, they neglected to mention you should have taken 2 years of HS chem as a pre-req (my school only even offered 1), and my foolish 18 y/o pride prevented me from switching to regular Gen Chem. To top it off, the prof is a notorious jackass whose divorce was finalized the semester I had him. I escaped with about the lowest C possible, which sits proudly on my transcript, and was the FIRST thing I was asked about in my only interview to date.