I worked in a hospital's lab one summer. The three things I remember the most are counting sperm under the microscope (which smells really really bad), helping out with Pap smear analysis (which looks really really bad), and being the pee-on intern who, yep, gets first dibs in processing the urine samples as they come in (which smell really really bad).

Worst job? Yes and no. I went on to do a PhD in bacterial genetics.