if you are really interested in learning the intricate details of the language , then you must get "the C Programming Language" by Kernighan and Ritchie, the creators of C. get the solution book too-"the C answer book" since the problems of the book are really challenging.
Let Us C is a good book to start with. But i ve seen a lot of students using it as a reference. i ve seen a lot of guys preparing for interviews with let us C. it is a very very basic book. in fact the people who take the interviews sometimes have asked - which C book did you read from. and if they hear Kanetkar they literally laugh on your face. if you are preparing for an interview or need a reference you have to get "C programming FAQs" by Steve Summit. it is nothing but a collection of questions raised on the usenet when C was in glory.
i ve heard that kanetkars other books like pointers and data structures are good. i have the data structures book of kanetkars . i frankly hate his style. only the cd with a few flash animations of building , editing data structures helped me. the text book is horrible. if you want to prepare for a class test or exam with all possible programs then rush and get the kanetkars series. if you want to understand concepts with algorithms(and then code stuff yourself) rather than raw code (without comments), like kanetkars then you need something better like tenenbaum or the others i mentioned above.