- 18.100 - Not really necessary; the class provides an introduction to mathematical rigor.
- Munkres - Excellent. Very clear and precise. The class covers the first half.
Point set topology, in and of itself, is fairly worthless, but since it is used almost universally in mathematics, so you have to learn it at some point. Except for ~3 theorems, the class is a bunch of definitions and straight-forward consequences (the definitions, though, are far from obvious). In my opinion, it's not necessary to devote an entire semester to the subject, and it seems possible to pick up the textbook and learn the material over the summer or something.