Here are several links to what I think are the most useful on-line personality assessments.
The goal is to give you more information about yourself and enable you to better match your personality and tendencies to a work situation/culture/people so you are happiest, most productive and effective. It is important to adapt the findings to aid your job search. An interpretive report will help, and you can get even more value by discussing the findings with a career coach or certified assessment provider.
1) The DISC Profile gives you a look at how you respond to your environment especially geared toward work. The basic on-line assessment currently costs $25.95, which I think is all you need. More in-depth reports are available that bring the cost to $59.95. Click to see a sample report so you can make a more informed decision.
2) The grandmother of assessments, the Myers-Briggs Type Indicator (MBTI), can be taken on line. It involves a bit more work on your part, and a substantially greater financial outlay of $150. The cost is not only for taking the assessment but for going over it with a trained interpreter. That review will be helpful for you to gain more understanding of how/why MBTI can be useful in your work and life. You also get some booklets sent to you along with a tailored report. For another $15, you can get a personalized career report.
3) A free assessment based somewhat on MBTI is the Keirsey Temperaments . It is a "70 question personality instrument that helps individuals discover their personality type." You will get a free report after taking the assessment on-line.
4) Other free and pretty accurate assessments are at HumanMetrics.com; PersonalityTest.net which has more thoughtful questions, in my humble opinion; SimilarMinds.com; and, 41Questions. Three of the four pegged me as ENFJ and the last said I was ENFP. I usually test at ENFP through Myers-Briggs but my last one was several years ago. Thus these assessments may be telling me that I've changed somewhat over time.
If you use these free assessments, make sure you go to this Wikipedia article to get some interpretive information. Getting the MBTI itself would provide you with a baseline, as well as more interpretive information.