Confusion with Courant: Which of his two calculus books is THE one?

Since I've worked my way through Spivak's Calculus book, I thought I'd give Courant's allegedly fantastic exposition of the subject a go as well. However, I've run into a problem. People in stackexchange threads always praise and suggest Courant's Calculus without specifying whether that's supposed to be his "Differential and Integral Calculus" or his "Introduction to Calculus and Analysis" book.

So my question is: which one of these two is the "famous" and "legendary" Calculus book that everybody always talks about when the "great three" - Spivak, Apostol and Courant - are mentioned or recommended to people asking for a first course in calculus?

Note: I'm a math major. I'm mostly interested in what the oft-mentioned calculus book by Courant is, and not which of his two books would suit my prior exposure to calculus (Spivak) best in terms of the follow-up level. That is not to say I wouldn't appreciate an informed opinion on that matter, I certainly would (and I hope some experienced readers will be able to enlighten me), but I'm primarily asking this question to find out which is the more canonical one.

Differential and Integral Calculus is the classic. The first edition in English came out in 1934. Introduction to Calculus and Analysis is a somewhat modified version co-authored by Fritz John. Careful attention to either version will give you (just about the same) very good grounding in calculus, so you may want to read which ever one is easier to get a copy of. But if you want to read the classic, it's Differential and Integral Calculus.

Another very lovely, old calculus text is A Course of Pure Mathematics by G. H. Hardy. It's impossible to learn the subject from the book by Landau (also called "Differential and Integral Calculus"), but it's worth a look once you already know the subject.