How should Latin be taught?

There are so many Latin textbooks out there to choose from:  Jenney's, Oxford, Wheelock's, Ecce Romani.  Yet it seems like the methods for teaching Latin are pretty limited:  reading method, grammar translation method, and direct method.  I would love to think that the direct method of immersion and learning Latin in Latin is the best approach.  Is it?  Many of my students take Latin for only two years.  Where should the focus be:  learning the language itself or using the advantage of the English derivatives and links to English grammar to enhance their own primary language learning?  Learning Latin as a language or as some sort of complex, mathematical code that makes their minds really work?  I love Latin for itself, reading the literature in the original language.  BUT I know that many students take it for the bump of their SATs and to help them in their other classes.  That is an advantage to Latin, but should it be the main emphasis?   I really don't know the answer to that. After taking Latin for around 10 years in middle school, high school, and college, I realize that this answer isn't about me anymore.  It's about my students.  How do I need to teach to benefit them the most?