Depends on what YOU consider "worth the most." Criminal defense attorneys cannot charge a client a contingency fee in any state. That is illegal. A personal injury attorney can charge a contingency fee which ranges but is usually 1/3 to 40% of the case. So it depends on whose perspective you look at it from. If you think you need an attorney, you probably do - consult with one and then make an informed decision.
I am not sure what you mean either, by worth the most. Are you asking if those types of cases generate the most in fees? As noted by the other answers, each case is different and the fee to the attorney is controled by the complexity of the case or the recovery if an injury case. Other attorneys may recieve more in fees on an hourly rate - it all depends on the legal issues and the type of case.
Ron Slonaker, Attorney
This response is to provide general legal information and does not constitute legal advice nor should it be considered or viewed as forming any sort of attorney-client relationship and such information provided is viewable by the general public.