I pretty much always pay attention in class, and I honestly think it's the reason I ended up with good grades last semester. By the end of the semester, I knew exactly what each professor would be looking for on the exam, what they thought was important, and how they wanted to see issues analyzed, so I was able to tailor each exam to each professor. However, I've always gotten more out of lectures than books...maybe I'm just weird like that. I mean, everyone learns differently, so I think people should just do what works for them. Some people think lecturer's pointless, some think the reading's pointless, and some think everything's important. And I know some of each type who are in the top quarter at my school, so there's really no right answer.