I am a self studier of Calculus. I have quite a few books including Thomas. If you have intention to go far in Calculus, I think the clear winner is Calculus by Anton, Bivens and Davis. It might not be the easiest book to read and learn. BUT easy is not the most important with calculus if you are serious. I avoid this book at the beginning and stay with Sherman Stein and Thomas. Stein is particular easy. Problem is when the subject get harder towards the end, Stein started to fall apart. Thomas is better but not in the same league yet.
Anton present material in a very logical way, you have to learn the terminlogies and logical method. But once you follow, it is a better book by a lot. Some of the easier book tend to skip the more precise definitions that you think you can skip, but you really cannot. It will come back and bite you every single time. It is very very important to get the foundation right. If you start off with shaky foundation, it will be very hard to move pass the second semister. The multi-variable is where Anton shine. You will notice that's where the other books starting to get confuse. Anton with the straight procedure, no short cut approach really shine. When you get to the most confusing part...Line Integral, Vector Field, Divergence Theorem and Stoke's Theorem, Stein's book just fall apart, I wasted so much time on that stupid book going around and around. Even Thomas is not doing well. Then when I finally bite the bullet and get onto Anton, it was like a light bulb light up.
Anton is the only book I read that push in finding the surface integral using jecobian and cross product of two vectors which is the hardest to understand...but after wasting all the time with the other books, I conclude this is the best way. This book is a must have for self studier.
You really need to get at least 3 books for self study. Thomas might be a good second book because when you get too flustrated, Thomas might be able to throw you a life line with easier explanation. But stay with the Anton. I am still using the Anton as a reference when I am studying electrodynamics.
Now, if you just want to learn some calculus and have no intention to go beyond the second semister, Then Sherman Stein and Anthony Barcelos is a very easy book to learn at least the first one and half semister to the point of "methods of Integrations". It is very easy. Anything farther than that, dump that book. The lack of formal logic of Stein will not matter if you don't pursue higher math.