TITLE: Where to start learning Differential Geometry/Differential Topology?
QUESTION [30 upvotes]: I realize that this may be a very general question, perhaps even an unclear one (if it is I apologize), but as someone looking for the best way to start learning about these topics, I find that there is no clear path to learning Differential Geometry / Differential Topology, as there is with Analysis or General Topology, or even Abstract Algebra
For example in Analysis, most agree that Principles of Mathematical Analysis by Walter Rudin is the place to begin, for Topology, Munkres book is the standard reference, and for Algebra, most tend to use either Dummit and Foote, Artin, Fraleigh or Lang.
For Differential Geometry/Differential Topology, I find that there are no standard texts, the only one I know of is Lee's Introduction to Smooth Manifolds, however I feel I currently lack the prerequisites to tackle that book properly.
Now I understand that to recommend a book to someone, you would need some gauge of their mathematical ability/maturity, but it is next to impossible to demonstrate that, so instead I can give a list of books that I'm currently reading through, and plan to read through in the next 3-6 months.
What I'm currently reading

Principles by Mathematical Analysis (Baby Rudin)
Linear Algebra Done Right (by Sheldon Axler)
Vector Calculus, Linear Algebra, and Differential Forms: A Unified Approach (by Hubbard and Hubbard)

What I plan on reading soon

Calculus on Manifolds by Spivak
Topology by Munkres
Complex Analysis by Alfhors
Abstract Algebra by Dummit and Foote

But after that I'm lost as to where to go further. I'm lost between Analysis on Manifolds by Munkres, A Comprehensive Introduction to Differential Geometry by Spivak, and do Carmo's Differential Geometry of Curves and Surfaces.
Or should I just skip all those intermediate books and go straight to Lee's Introduction to Smooth Manifolds?

A Side note I find that the more challenging a book I read is, and the more I struggle through a book, I develop a deeper understanding of the topics in the book, and a greater appreciation of the subject I'm studying as a whole. Based on the books I've read/plan to read, please recommend books that are not easy, but difficult and challenging.

REPLY [21 votes]: It's been around 11 months since I first asked this question. I thought I would share my path to learning Differential Topology and Differential Geometry. Hopefully this will be of some help to others who are also hoping to learn Differential Topology and Differential Geometry.
Firstly I read most of the contents of the General Topology part of Munkres. I tried afterwards to go through Calculus on Manifolds by Spivak, but I got bored really quickly, and as a book I didn't particularly enjoy reading or working out of it that much.
So I jumped straight ahead to reading Topology from the Differentiable Viewpoint by Milnor, this quickly became one of my favourite books I've ever read. There was a saying I read somewhere on MathOverflow which said 

Run don't walk your way to Milnor's Topology from the Differentiable Viewpoint

That couldn't have been more true. (If as a reader to this answer, this is the most important thing to take away) You just need a bit of General Topology and the basics of multivariable calculus and linear algebra to tackle it. In it's short 50 pages, it takes you deep into Differential Topology. I'm planning on rereading it again.
I'm currently reading Differential Topology by Guillemin and Pollack which is a superb supplement to Milnor's book. 
The only drawback (although not a bad one) is with Milnor's and Guillemin and Pollack's books, all smooth manifolds are embedded in some euclidean space $\mathbb{R}^n$, and aren't abstract, though due to Whitney's Embedding Theorem this isn't too much of an issue.
I am also currently reading Introduction to Smooth Manifolds by John Lee which is an incredibly well written book, it's clear, filled with tons of examples and exercises. I've also browsed through Introduction to Manifolds by Tu but compared to Lee's book I don't use it as much.
Finally, I think a book that is worth mentioning is Introduction to Topological Manifolds also by John Lee which acts as a great first encounter to topological manifolds.