I agree, coming from the perspective of someone who went to school with 25,000 other undergrads, where it's hard to get to know faculty well. That said, you should try to get to know some senior faculty so that they can write you strong letters. To do that, I took some upper division classes and summer classes with smaller numbers of students and went to a lot of office hours (but for pete's sake, have something to talk about when you go to office hours).