As a graduate student at my university, I have the option many times of deciding what type of work I do for support. The two basic options are to teach either a calculus or college algebra course, or to act as TA (i.e. just hold office hours for the class, but do not teach it) and grader for an upper division (300-400 level) or early graduate course (500 level).
Is there a hard and fast rule as to which route is a better one to take? That is, if I spend all my time TAing for say a 400 level algebra class in Galois theory, will this reflect worse on me than if I had taught several sections of introductory calculus? I am looking at this especially from the perspective of being a MS student and trying to get into a doctoral program.
I prefer to be involved in more advanced classes as opposed to teaching a lower division course, but I do not want to cripple my chances for getting admitted into a PhD program in the near future.