I am just wondering what is the most common, or most used, block cipher mode used to goes with CTS? ECB or CBC?
There is a NIST definition of CTS (CipherText Stealing) mode at: http://csrc.nist.gov/publications/nistpubs/800-38a/addendum-to-nist_sp800-38A.pdf.
The title of that addendum answers the question: "Recommendation for Block Cipher Modes of Operation: Three Variants of Ciphertext Stealing for CBC Mode".
The paper is also useful to understand that there are many different ways to do ciphertext stealing.