TSQL Querying - By Itzik Ben-Gan Et al
TSQL Fundamentals - By Itzik Ben-Gan
Microsoft SQL Server 2012 High Performance T-SQL Using Window Functions - By Itzik Ben-Gan
SQL Server 2012 TSQL Recipes - By Jason Brimhall and Wayne Sheffield
Microsoft SQL Server 2012 Internals - Karen Delaney and Bob Beauchemin
You might see an pattern developing with the author of some of these books Itzik's books are very good you can't help but learn a lot from them. The other two are really useful too
Update 13th September 2016Thanks to Steve Hindmarsh for his comments. Steve recommends the following books. I have read the Antipatterns book a while ago...although i don't still have a copy. It is a good book.
SQL Antipatterns: Avoiding the Pitfalls of Database Programming by Bill Karwin
Steve also recommended the following
Defensive Database Programming - By Alex Kuznetsov.
I have read this book too. You can get a printed copy from amazon by following the link. You can however get the ebook in pdf format free from sqlservercentral.com its well worth a read