suggest textbook on calculus I read single variable calculus this semester, and the course is using Thomas Calculus as the textbook. But this book is just too huge, a single chapter contains 100 exercise questions! Now I'm looking for a concise and complete textbook. I'm not interested in routine, computational exercises, but rather some challenging problem sets.
I have quite a strong basic knowledge of calculus from high school, but I still have difficulties in solving a few questions from past exam papers. So I'm looking for more challenging exercises. In fact, I'm looking forward to solving Putnam level questions.
Please suggest some textbooks with these features. Thanks in advance.
 A: You might want to look at Chicago undergraduate mathematics bibliography:

Of course, as we all know, the One True Calculus Book is
Spivak, Calculus
This is a book everyone should read. If you don't know calculus and have the time, read it and do all the exercises. Parts 1 and 2 are where I finally learned what a limit was, after three years of bad-calculus-book “explanations”. The whole thing is the most coherently envisioned and explained treatment of one-variable calculus I've seen (you can see throughout that Spivak has a vision of what he's trying to teach).
The book has flaws, of course. The exercises get a little monotonous because Spivak has a few tricks he likes to use repeatedly, and perhaps too few of them deal with applications (but you can find that kind of exercise in any book). Also, he sometimes avoids sophistication at the expense of clarity, as in the proofs of Three Hard Theorems in chapter 8 (where a lot of epsilon-pushing takes the place of the words “compact” and “connected”). Nevertheless, this is the best calculus book overall, and I've seen it do a wonderful job of brain rectification on many people.
[PC] Yes, it's good, although perhaps more of the affection comes from more advanced students who flip back through it? Most of my exposure to this book comes from tutoring and grading for 161, but I seriously believe that working as many problems as possible (it must be acknowledged that many of them are difficult for first year students, and a few of them are really hard!) is invaluable for developing the mathematical maturity and epsilonic technique that no math major should be without.
Other calculus books worthy of note, and why:
Spivak, The hitchhiker's guide to calculus
Just what the title says. I haven't read it, but a lot of 130s students love it.
Hardy, A course of pure mathematics
Courant, Differential and integral calculus
These two are for “culture”. They are classic treatments of the calculus, from back when a math book was rigorous, period. Hardy focuses more on conceptual elegance and development (beginning by building up R). Courant goes further into applications than is usual (including as much about Fourier analysis as you can do without Lebesgue integration). They're old, and old books are hard to read, but usually worth it. (Remember what Abel said about reading the masters and not the pupils!)
Apostol, Calculus
This is “the other” modern rigorous calculus text. Reads like an upper-level text: lemma-theorem-proof-corollary. Dry but comprehensive (the second volume includes multivariable calculus).

A: If you are looking for some challenging calculus problems, I would suggest looking at the HMMT (Harvard-MIT Mathematics Tournament) problems archive. Take a look at the calculus test for the years 1998-2011. I don't think these problems are the routine exercises that you have grown weary of in Thomas' Calculus.
If you want another book that may suit your taste, I recommend "Introduction to Calculus and Analysis" by Richard Courant and Fritz John. I think the problems are a bit harder than those in Thomas' text. But more importantly, Courant and John give a lot of motivation for calculus through discussing its relevance to the physical world (there is even discussion of Fourier Series in the study of a vibrating drum). 
Courant and John also introduce some concepts of modern analysis (calculus done more rigorously) such as monotone sequences, a precise discussion of a limit, etc towards the end of the book, if that interests you. 
Last but not least, I see that you mentioned the Putnam. I think a great book for doing calculus problems that may prepare you for the Putnam is Titu Andreescu's book- "Problems in Real Analysis: Advanced Calculus on the Real Line".
Andreescu's texts are known to be useful in preparing students for mathematics competitions. In this textbook, Andreescu exposes you to a lot of techniques (especially in dealing with inequalities) that may help you with the Putnam. You may also learn some analysis along the way, but since he is dealing only with the real line, he doesn't "weigh you down" with various topological concepts that may or may not interest you. If you have mastered the concepts of calculus and are looking for a challenge, this book may be for you. 
Good luck!
A: I was in a similar situation a couple of months ago.So i decided not to read a calculus text untill i watch a video lecture like single variable calculus from MIT. {I'am a self learner by the way}.I would refer to a text only when the situation arises,say for more problem sets i would refer to not one but multiple texts like Ron larson/Edwards calculus.James Stewart's calculus text and many others.
As of now i'am watching Video tutors from Thinkwell,TTC and many others on youtube.I find youtube to be the worlds best resource for learning math and i'am having loads of fun with it.I suggest you do the same.
And not to forget video's from Patrick JMT and khan academy are just amazing.
A: I gathered some online calculus text-books on My blog. Hope these will be useful for you.
EDIT: In that list, I mostly liked the Calculus book by Stewart.
A: Here is a new addition to the literature of books treating Calculus more rigorously than usual and which contains several challenging problems:
The How and Why of One Variable Calculus by Amol Sasane, published by Wiley in August 2015.
A google preview can be found at
https://books.google.se/books?id=HMnvCQAAQBAJ&printsec=frontcover&dq=sasane+calculus&hl=sv&sa=X&ved=0CCQQ6wEwAGoVChMIsYe1utLQyAIVJotyCh2XsQaF#v=onepage&q=sasane%20calculus&f=false
and some sample material from the book can also be found on the publisher's website for the book, at:
http://eu.wiley.com/WileyCDA/WileyTitle/productCd-1119043387.html
A: I was in the same situation. I tried to work with Spivak's book. It was not very practical for selfstudy since the exercises are pretty tough. I could only solve every 10th problem in chapter one. 
Thus I decided to look for something else, that would be less time consuming. 
I tried Thomas' Calculus, a newer edition, which I do not recommend at all. The exercises are so simple you won't be challenged at all.
Then I found Marsden and Weinstein's Calculus 1-3. These books are just marvellous. You find pdfs online, i checked them and bought all the books. It's already 30 years ago that these books were published and they are not as much appreciated as they should be. Their approach to single variable is unique. The books have a good choice of exercises in varying difficulty. Also there are a student guide and exams that help understanding the material and checking the progress.
A: I would highly recommend- Calculus made Easy by Silvanus P Thompson, Calculus by Michael Spivak (For Basic Learning) and Calculus- Vol.1 & 2 by Tom M Apostol (For Advanced Learning).
For further Reference or Future guides: http://math-blog.com/mathematics-books/
A: Here's a new book to add to the growing list of books that handle Calculus more strictly than normal and include numerous hard problems:
https://techvoke.com/couchtuner/
https://books.google.se/books?id=HMnvCQAAQBAJ&printsec=frontcover&dq=sasane+calculus&hl=sv&sa=X&ved=0CCQQ6wEwAGoVChMIsYe1utLQyAIVJotyCh2XsQaF#v=onepage&q=sasane%20calculus&f=false
Amol Sasane's book The How and Why of One Variable Calculus was released in August 2015 by Wiley. I have attempted a newer edition of Thomas' Calculus, which I do not recommend. You won't be challenged at all because the workouts are so basic.
