Okay, I'll tell you.  It's my appendix.  I went into the hospital on September 12th with abdominal pain and emerged later the same day without my appendix!  Being a nurse myself, it was interesting to be the patient and experience everything from the other side.  I am happy to say I was treated very well.  The most painful part actually was after I came home when the medical bills started arriving.  I have insurance, thankfully.  If this had happened a few months earlier I wouldn't have had it yet (I had to be at my new job for 3 months before I was eligible for insurance).  Basically, once I meet a $2000 deductible for the year, my insurance pays 80% of costs, I pay 20%. 
Here's a rundown of the bills I've received so far.  The first number is the total bill.  The second number is after insurance paid their portion, so it's my responsibility to pay.
-  ER physician exam: $576.00, $104.20
 - IV fluids (2 bags Normal Saline): $197.00, $39.40
 - IV antibiotics: $59.00, $11.80
 - CAT scan of the pelvis with contrast: $213.00, $42.60
 - CAT scan of the abdomen with contrast: $235.00, $47.00  
 - Pathologist's fee (for examining the appendix once it was removed): $145.00, $27.00
 - Anesthesiologist's fee: $1078.00, $338.90
 - Surgeon's fee (it was a laparascopic procedure): $3300.00, $790.00
 
Total without insurance: $5803.00
Total I will have to pay: $1400.90
Wow.  Thank goodness for insurance.  Thank goodness I have a job that pays well so I can afford to pay the bills that I still owe even with insurance.  What a crazy health care system.