The Psychology Quiz: This one is great. You asked to visualize ten scenes and respond with a short answer. Results are immediate and very fun...!
GRE Standard Test: (3MB pdf) Here's a link to their HomePage with bivy of resources.
Periodic Table Quiz: Think you know the periodic table pretty well? Just fill in the elements you know.
The Mensa Workout: I highly recommend this test to anyone that thinks they may be of greater than
average smarts.
Human Anatomy Quiz: Go through a cadavor and name what you see. Tough and extensive
Goldberg Depresion Inventory: One of the better quizes I've found dealing with depression. "Use this brief, time-saving questionnaire to help determine if you need to see a mental health professional for diagnosis and treatment of depression, or for tracking your depression on a regular basis."
World's Smallest Political Quiz: I really like this one. A quick and accurate test to better understand your political philosophy. I had a few of my freinds with more bias political views take it and they agreed.
Trivial Pursuit: This is one of the many multiplayer games offered by www.Station.Sony.com.
Organic Chemistry: This multiple choice test covers the basics of O. Chem. Easy to hard questions. By Arthur Winter of Frostburg State Univ.
The Color Quiz: Based on a series of colors you choose, this quiz outputs details of your personality. Found it to be quite accurate in my case. You can easily email the results at the end.
Social Work Carrers Quiz: If your interested in a career in social work, this is a great resource. 12 quizes