I got my money's worth off of Top Score because it really stresses the time element. Subject-wise, I found it best prepares you for Reading Comprehension because you have to get used to scanning the words in a little box & using your mouse rather than just having the entire reading page right in front of you (as many practice exams do). The DAT is more about STRATEGY than it is about books smarts. Top Score is best in helping you polish your strategy with respect to time management, stress, & even guessing. For Bio, G-chem, O-chem, & math I would go with Kaplan & Princeton review practice exams. For PAT, I would go with Kaplan & Barrons. Remember, the DAT will offer you the opportunity to get the right answer without knowing the material by eliminating the impossible... so dont just study hard, study smart! 😉