I'm fond of baby Rudin: elegant presentation, "clever" proofs, certain terseness, difficult exercises, etc. I'm working up my enthusiasm to seek similar textbooks in other areas of math, e.g. linear algebra, abstract algebra, ODE, number theory. Below are some books I want to exclude:
Zorich's analysis—it certainly offers a higher-level view of analysis, but too wordy and explanatory for me.
Lang's Algebra—its selected proofs are concise and elegant, but it's intended to serve as a reference book.
Arnold's ODE—it's excellent, but not at all alike.
Please provide the closest one you've read. It would be appreciated if you can suggest books in branches that haven't already been touched on by other answers so as to diversify the list. I believe this list will be favorable to those who enjoy Rudin's style as much as I do. Please inform me if this is a duplicate, I'll close it immediately (I can't be sure even I've already looked it up). Thanks in advance.